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Release Notes for Cisco IOS Release 12.1(3)DA for Cisco DSLAMs with NI-2

Release Notes for Cisco IOS Release 12.1(3)DA for Cisco DSLAMs with NI-2

August 28, 2000


Note   You can find the most current Cisco IOS documentation, including release notes, on Cisco Connection Online (CCO). These electronic documents may contain updates and modifications made after the hard copy documents were printed.

These release notes describe features and caveats in Cisco IOS Release 12.1(3)DA for the Cisco 6100, Cisco 6130, Cisco 6160, and Cisco 6260 digital subscriber line access multiplexers (DSLAMs).

For pointers to more information about the Cisco 6160, the Cisco 6260, the Cisco 6130, and their software, refer to the Related Documentation. To learn more about caveats, visit Cisco's web site—See the Cisco Connection Online for details. Information about electronic documentation can be found in both the Cisco Connection Online and in the Documentation CD-ROM.

Contents

This document contains the following topics:

System Requirements

Cisco IOS Releases 12.1(3)DA, 12.1(2)DA, 12.1(1)DA1, and 12.1(1)DA run on these DSLAM systems:

New and Changed Information

This section provides new and changed information for Cisco IOS releases.

New Features in Release 12.1(3)DA

This section provides information about the latest features in Cisco IOS Release 12.1(3)DA.

ATUC-1-4DMT2-ISDN Line Card

This release supports the quad port ATUC-1-4DMT-ISDN line card. This line card provides four ADSL/DMT ports per card. With this card, the Cisco 6260 supports operation over POTS and over both 4B3T and 2B1Q ISDN line coding.

New Features in Release 12.1(2)DA

This section provides information about the latest features in Cisco IOS Release 12.1(2)DA.

Eight-Port IDSL ITU-C Line Card

This release supports the 8-port IDSL ITU-C line card. With this 8-port card, the Cisco 6160 can support up to 256 IDSL subscribers. The IDSL line card uses 2B1Q line coding and offers configurable data rates of 56 kbps, 64 kbps, 128 kbps, and 144 kbps. The card also provides PPP (RFC 1549) to PPPoATM (RFC 2364) translation and FRF.8 Frame Relay to ATM service level interworking. In this release, the IDSL line card operates in the Cisco 6160 DSLAM only.

New Features in Release 12.1(1)DA1

This section provides information about the latest features in Cisco IOS Release 12.1(1)DA1.

Software Supports Alcatel DSL Chip Set-Based CPE

This DSLAM software image is interoperable with most CPE devices based on the Alcatel DSL chip set (no new hardware is required), including the Cisco 827 CPE, which is also based on Cisco IOS. This image provides enough performance to support deployment of DSL services in actual field conditions, but all CPE modems do not perform equally well (your mileage will vary).

Quad-Port DMT Card Supports G.lite and G.DMT

The ATUC-1-4DMT2 line card now supports the G.992.1 (G.DMT) and G.992.2 (G.lite) standards.

New Features in Release 12.1(1)DA

This section provides information about the latest features in Cisco IOS Release 12.1(1)DA.

Release 12.1(1)DA Supports the Cisco 6160 DSLAM

The Cisco 6160 is a multiservice DSLAM designed for markets in North America. The Cisco 6160 is a NEBS-compliant platform that supports up to 128 subscribers per chassis, with plans to support 256 subscribers in a future release. Initially, subscriber lines can be ADSL with either carrierless amplitude modulation/phase modulation (CAP), discrete multitone (DMT) T1.413-1998, Issue 2-compliant, or SDSL. (IDSL will be available shortly.) Up to 13 Cisco 6160 chassis can be linked together through the use of advanced, fair-service subtending. OC-3c and DS3 trunk and subtending interfaces are available now; T1 IMA will be available in the future. Optional support for analog voice telephony (POTS, or plain old telephone service) is also available through a companion POTS splitter available from ADC. The Cisco 6160 runs the widely deployed Cisco IOS software.

Availability and Compliance

The Cisco 6160 is designed for 23-inch deployments requiring NEBS compliance and compatibility with North American telephone network requirements. Cisco technical and customer service support teams ensure the highest level of customer care and service support available.

Advanced Services ATM Architecture

The Cisco 6160 internal design is based on a high-performance ATM switching architecture that includes more than 1 million cells of buffering, support for multiple ATM quality of service (QoS) levels, and a variety of ATM traffic management and shaping capabilities.

Scalability with Fair-Service Subtending

The Cisco 6160 supports subtending of up to 13 shelves (chassis) of user traffic all concentrated onto a single network WAN interface port. A variety of WAN and subtending interface port configurations are available, allowing for flexible service architecture design and optimized cost. The Cisco 6160 subtending architecture provides fair and prioritized access to network bandwidth for all subscriber traffic, ensuring sustained throughput and performance for all users.

Standards-Compliant ADSL Support

The Cisco 6160 supports a quad-port flexi line card that can be configured for either CAP or DMT T1.413-1998 Issue 2-compliant line encoding, ANSI T1.413 issue 2 (ATM mode), G.992.1 Annex A, G.992.2 Annex A, and configurability between G.lite and G.dmt/T1.413.

Switched Virtual Connections

Support for ITU and ATM Forum UNI 3.0, 3.1, and 4.0 switched virtual connections (SVCs) provides end-user applications with real-time access to bandwidth and QoS. Support for Private Network Node Interface (PNNI) call routing and Call Admission Control (CAC) is also included.

Soft PVC Provisioning

ATM signaling can be used for automated provisioning of ATM virtual circuits. This capability, also referred to as soft permanent virtual connections (soft PVCs), greatly reduces the time and cost of manual, node-by-node PVC provisioning.

Life-line POTS Splitter Support

Optional support for voice telephone service (POTS) is accomplished through use of POTS splitter equipment available from a third party, ADC Telecommunications. This POTS splitter solution is optimized for international copper access networks and is designed to ensure that basic telephone service is always available, a feature known as life-line POTS.

Splitters and cable kits are not OEM from Cisco and are available only through ADC. ADC offers several splitter solutions; contact ADC to get additional information:

Rodney McCrea
Rodney_McCrea@adc.com
(612) 403-8922

New Flexi and SDSL Line Cards

Two new quad-port line cards are introduced in this release for use with the Cisco 6160 and Cisco 6130:

With these line cards, the Cisco 6160 supports up to 128 ports per shelf. New eight-port line cards, available soon, will double the capacity of the system to 256 ports. Line card options that are planned for future releases include G.SHDSL.

New DMT Performance MIB Support

This release supports 96 buckets of 15-minute interval, previous and current 1-day interval DMT performance statistics.

Support for New VPI/VCI Combinations

To enable migration from NI-1 to NI-2 without reconfiguring CPEs in the field, in this release the NI-2 DSLAMs support both VPI=1, VCI=1 and VPI=1, VCI=0 configurations on subscriber ports.

Changes to Default Values in DSL Profiles

The following default values have changed:

Profile Configuration Command New Default Old Default

dmt margin

downstream 6
upstream 6

downstream 3
upstream 3

dmt framing-mode

mode3

mode1

dmt training-mode

quick

standard

New Microcode for ATUC-1-4DMT Line Card

Cisco IOS Release 12.1(1)DA includes new DSP microcode for the ATUC-1-4DMT2 line card for Cisco 6260 and Cisco 6130 DSLAMs.


Caution   When you boot the DSLAM for the first time after installing Cisco IOS Release 12.1(1)DA, the DSLAM downloads new microcode to the 4DMT-2 line cards. The microcode download requires about 10 minutes. During the download period, the Active LED on each line card blinks and the DSLAM does not pass data. Until the download is complete, do not remove cards from the chassis. Do not reboot the chassis. If you interrupt the download, the line card's flash memory might be damaged, making it necessary to replace the card. When the download is complete, the Active LEDs on the line cards stop blinking and the lines train as usual.

You can track the status of a microcode download through software using the command show dsl int atm slot/port. In the resulting display, look at the Line Status field. If the Line Status field says DOWNLOADING MICROCODE, wait a few minutes and check again.

Limitations and Restrictions

This section describes the limitations and restrictions for Cisco IOS DSLAM releases.

Cisco IOS Release 12.1(3)DA

The limitations and restrictions for Cisco IOS Release 12.1(3)DA are the same as those listed for Cisco IOS Release 12.1(2)DA, below.

Cisco IOS Release 12.1(2)DA

The following restrictions apply to this release:

    1. If you are using Cisco DSL Manager (CDM) Version 1.0 or 1.1 software to manage your existing DSLAM network:

    2. Cisco IOS Release 12.0(8)DA2 or greater is required for Cisco 6260 and Cisco 6130 systems that contain new 4DMT-2 cards (revision 800-05262-03 or greater). Releases 12.0(8)DA2 and above are also compatible with earlier revisions of the 4DMT line card.

If you need to fall back to an earlier release, note the following restrictions:

    3. Cisco IOS Release 12.0(8)DA4 runs only on this hardware:

    4. The VP tunneling feature cannot be used in conjunction with VCs outside of VP tunnels.

Cisco IOS Release 12.1(1)DA1

The limitations and restrictions for Cisco IOS Release 12.1(1)DA1 are the same as those listed for Cisco IOS Release 12.1(1)DA, below.

Cisco IOS Release 12.1(1)DA

The following restrictions apply to this release:

    1. If you are using Cisco DSL Manager (CDM) software to manage your existing DSLAM network:

    2. Cisco IOS Release 12.0(8)DA2 or greater is required for Cisco 6260 and Cisco 6130 systems that contain new 4DMT-2 cards (revision 800-05262-03 or greater). Releases 12.0(8)DA2 and above are also compatible with earlier revisions of the 4DMT line card.

If you need to fall back to an earlier release, note the following restrictions:

    3. Cisco IOS Release 12.0(8)DA4 runs only on this hardware:

    4. The VP tunneling feature cannot be used in conjunction with VCs outside of VP tunnels.

Important Notes

This section provides important information about Cisco IOS DSLAM releases.

Soft PVC Address Changes Upon Upgrade to 12.1(3)DA or Later

When you upgrade from a previous release to 12.1(3)DA, the default soft PVC addresses on all interfaces change. This only occurs when you upgrade to release 12.1(3)DA from a previous release. This will not happen when you upgrade to future releases from 12.1(3)DA.

Workarounds:

Configuring Cisco Routers for Use with IDSL

If you wish to use a Cisco router for an IDSL application and the router is running a Cisco IOS release prior to 12.1, you must configure the ISDN switch type. If you do not configure the ISDN switch type on the Cisco router, the router's BRI interface may not come back up after the IDSL line goes down and back up.

To prevent this problem from occurring, execute the isdn switch-type basic-ni command in global configuration mode on the router.

This problem does not occur if the Cisco router is running Cisco IOS Release 12.1 or later.

Upgrading from Cisco IOS 12.0(x)DA to 12.1(x)DA or Higher

After you upgrade a DSLAM from Cisco IOS Release 12.0(x)DA to 12.1(x)DA, you might experience a problem that results from a change in some of the DMT defaults in the DSL profiles. The changes, which are listed in the "Changes to Default Values in DSL Profiles" section, affect the training mode, overhead framing, and DMT margin parameters.

The problem is triggered when you edit your DSL configuration profiles after upgrading to Cisco IOS Release 12.1(x)DA.

The system checks its startup configuration file for a release number, and if it finds a number earlier than 12.1, it automatically adds the following commands to the profile whenever you edit the profile. These commands set the profile to use the old default values for training mode, overhead framing, and DMT margin.

dmt training-mode standard dmt overhead-framing mode1 dmt margin downstream 3 upstream 3

The commands are added so that the changed defaults in Cisco IOS Release 12.1(x)DA will not affect your configuration. However, the system continues to add the commands to your configuration every time you edit profiles, unless your startup configuration file contains a 12.1 release stamp.

Workaround: Follow these steps. Start with Step 2 if you have already completed the upgrade.


Step 1   Reboot the DSLAM after you upgrade to Cisco IOS Release 12.1(x)DA or higher.

Step 2   Issue the command copy running-config startup-config. Now the startup configuration file has a 12.1(x)DA stamp in it.

Step 3   Reboot the DSLAM again.


Now you can change the configuration without difficulty. [CSCdr66665]

Assigning VPI Values to Shaped VP Tunnels

This release supports the full range of VPI values: 0 to 255. However, if you configure VP tunnels with traffic shaping, you can use only 32 VPIs out of that range. If you have not yet assigned any VPIs, all values from 0 to 255 are available. Once you start assigning VPIs, however, the assigned VPIs limit the VPIs that remain. (You assign VPIs using the atm pvp or atm pvc commands.)

After a particular VPI value is assigned to a shaped VP tunnel, every 32nd VPI value above and below the first one is eliminated—that is, the original value modulo 32. For example, if you assign VPI 94 to a shaped VP tunnel, the following VPI values become unavailable for any purpose: 30, 62, 126, 158, 190, and 222.

To avoid problems, choose a block of 32 consecutive VPI values (for example, 0 to 31 or 101 to 132). The software rejects invalid VPI values.

Installing Multiple Cisco 6160 Chassis in an Equipment Rack

You can install multiple Cisco 6160 chassis within a telco equipment rack. A standard seven-foot equipment rack can house four Cisco 6160 chassis, stacked one on top of another. This configuration maximizes the DSL density within a seven-foot rack. However, if space is available or if you are interested in using multiservice capabilities that the chassis will support in the future, Cisco recommends that you install no more than three Cisco 6160 chassis within a seven-foot rack. Leave a space of at least 2.5 rack units (4.375 inches, or 11.1 cm) beneath each chassis for future cable management use.

Synchronizing the Management Database

If you use both the Cisco DSL Manager (CDM) application and the command line interface (CLI) to configure and manage your DSLAMs, you must the synchronize the CDM to your management database on a regular basis. (If you use only the CDM or only the CLI, you need not synchronize your database.) Refer to the release notes for the Cisco DSL Manager 2.0 or later for more information.

Console Logging

Turn console logging off if you plan to reboot the DSLAM. Turn console logging back on after the system comes up. (Console logging is turned on by default.) Use the global configuration commands no logging console (to turn the feature off) and logging console (to turn it on).

If console logging is on when the system reboots, the large volume of console messages consumes CPU time. As a result, the system comes back up more slowly and line cards might reload repeatedly, causing further delays.

Caveats

This section describes unexpected behavior in the system. A tracking number, if one exists, is provided in square brackets at the end of each description. Please refer to the tracking number if you communicate with Cisco Systems about any of these issues.

Open Caveats—Release 12.1(3)DA

The caveats in this section apply only to IOS Release 12.1(3)DA. Other open caveats that apply to this Release 12.1(3)DA are described in the "Open CaveatsRelease 12.1(2)DA" section, "Open CaveatsRelease 12.1(1)DA1" section, and "Open CaveatsRelease 12.1(1)DA" section.

Cannot reenter ...enable traps alarms ... after it is removed

If you disable snmp-server traps alarms with the no snmp-server enable traps alarms command, you cannot reenable this feature with the snmp-server enable traps alarms command.

Workaround: Use the command snmp-server enable traps alone to add all trap type options. Then you can disable the unwanted trap types one by one. [CSCdr64678]

Interoperability Problems

Alcatel-Based CPE—Mode Returned G.DMT instead of T1.413

If the CO line card requests T1.413 mode, the return value is decoded incorrectly by the Globespan chipset for Alcatel-based CPEs.

Workaround: The operation of the CPE is not affected. The correct mode is being used. Ignore the reported mode. [CSCdr58384]

Alcatel-Based CPE—Line Drops, < 8K FT. and Bit Rate below 512Kbps

There is a performance issue when the line length is less than 8 K feet with LOW noise, and the downstream bit rate is less than 512 kbps.

Workaround: Provision the downstream bit rate to be 512 K or above. [CSCdr63938]

Flexi Line Card Problems

This section describes problems with the flexi line card.

NI2/6160 Allows CPE to Train with Incorrect Mode

When the line card operating mode is set to either G.DMT or G.lite, the resulting operating mode depends on the CPE operating mode. Thus, when the CPE is set to G.lite, it is trained to G.lite even though the line card is set to G.DMT and vice versa.

Workaround: Make sure the mode at the CPE end matches the mode set at the DSLAM end. [CSCdr94959]

ATUC-1-4DMT2-I Line Card Problems

This section describes problems with the ATUC-1-4DMT2-I line card.

With Trellis Enabled, Errored Seconds are High

Enabling DMT trellis line coding on the 4xDMT/ISDN ADI-based line card can decrease link reliability by causing problems passing data due to errored second events and data corruption in the downstream and upstream directions. ADI/Aware has a known problem where high errored seconds may result if trellis coding is turned on. This problem is not scheduled to be fixed in the 2.0 release, which is currently where the 4xDMT/ISDN code is branched.

On the 4xDMT/ISDN ADI-based line card, having trellis coding enabled will decrease link reliability by causing problems training or passing data. There is no way to accurately predict when it will be reliable. Therefore, trellis coding is disabled by default on the NI-2 to ensure that it is not accidentally enabled with the 4xDMT/ISDN line card.

Workaround: DMT trellis line coding is not enabled by default on the NI-2, because it is not supported on the 4xDMT/ISDN ADI-based line card. [CSCdr92590]

Some Trains in Quick Mode will have High Errored Seconds

This problem occurs at long loop lengths (11500 feet and above) when using the quick training mode of the 4xDMT/ISDN ADI-based line card. It can decrease link reliability by causing problems passing data due to errored second events and data corruption in the downstream direction.

On the 4xDMT/ISDN ADI-based line card, using the quick training mode at long loop lengths (3600 m and above) will decrease link reliability. The link will train at a higher data rate, but at lower downstream margins (:for example, 1 or 2 dB) rather than training at a lower data rate and maintaining the requested downstream margin (:for example, 6 dB). This can decrease link reliability by causing errored second events and data corruption in the downstream direction due to the acquired lower downstream margins.

Workaround: Use the standard training mode to train up the link at long loop lengths (11500 feet and above). [CSCdr93540]

Reported Margins do not Match Selected Margins

This problem is identical to the problem described in DDTS report CSCdm89068, which describes the same symptoms that appear when using the ATUC-1-4DMT line card.

In some situations, the reported (actual) margins may be higher than the configured values. Depending on the port configuration, there are effective minimum end-to-end margin values for combinations of parameters including:

Workaround: If you configure the margins for a port below these effective minimum margins, the system accepts the margin configuration, but the margin values that are actually used and reported are the effective minimum end-to-end values. The actual margins are essentially clipped at these effective minimum values. [CSCdr93546]

The effective minimum margins for the downstream and upstream directions are given in the following tables:


Table 1: Minimum Effective Downstream Margins (dB)
Train Mode Frame Mode Intlv >0 Trellis Coding Ckbytes >0 Downstream Bit-rate Range (kbps)
32-640 672-768 800-3040 3072-6112 6144-8032

X

X

X

X

No

0

0

0

0

0

Quick

0,1

No

Disabled

Yes

0

5

5

4

5

Quick

0,1

No

Enabled

Yes

0

6

6

5

6

Quick

0,1

Yes

Disabled

Yes

0

6

6

5

6

Quick

0,1

Yes

Enabled

Yes

0

7

7

6

7

Quick

2,3

No

Disabled

Yes

0

0

5

4

5

Quick

2,3

No

Enabled

Yes

0

0

6

5

6

Quick

2,3

Yes

Disabled

Yes

0

0

6

5

6

Quick

2,3

Yes

Enabled

Yes

0

0

7

6

7

Stnd.

0,1

No

Disabled

Yes

2

2

2

1

2

Stnd.

0,1

No

Enabled

Yes

3

3

3

2

3

Stnd.

0,1

Yes

Disabled

Yes

3

3

3

2

3

Stnd.

0,1

Yes

Enabled

Yes

4

4

4

3

4

Stnd.

2,3

No

Disabled

Yes

2

2

2

1

2

Stnd.

2,3

No

Enabled

Yes

3

3

3

2

3

Stnd.

2,3

Yes

Disabled

Yes

3

3

3

2

3

Stnd.

2,3

Yes

Enabled

Yes

4

4

4

3

4


Table 2: Minimum Effective Upstream Margins (dB)
Train Mode Frame Mode Intlv >0 Trellis Coding Ckbytes >0 Upstream Bit-rate Range (kbps)
32-640 672-768 800-864

X

X

X

X

No

0

0

0

Quick

0,1

No

Disabled

Yes

0

5

5

Quick

0,1

No

Enabled

Yes

0

6

6

Quick

0,1

Yes

Disabled

Yes

0

6

6

Quick

0,1

Yes

Enabled

Yes

0

7

7

Quick

2,3

No

Disabled

Yes

0

0

5

Quick

2,3

No

Enabled

Yes

0

0

6

Quick

2,3

Yes

Disabled

Yes

0

0

6

Quick

2,3

Yes

Enabled

Yes

0

0

7

Stnd.

0,1

No

Disabled

Yes

2

2

2

Stnd.

0,1

No

Enabled

Yes

3

3

3

Stnd.

0,1

Yes

Disabled

Yes

3

3

3

Stnd.

0,1

Yes

Enabled

Yes

4

4

4

Stnd.

2,3

No

Disabled

Yes

2

2

2

Stnd.

2,3

No

Enabled

Yes

3

3

3

Stnd.

2,3

Yes

Disabled

Yes

3

3

3

Stnd.

2,3

Yes

Enabled

Yes

4

4

4

IDSL Line Card Problems

This section describes problems with the IDSL line card.

Clocking Problem

The following are clocking problems with the IDSL line card.

Workaround: Remove, then reinsert, the line card from the DSLAM chassis. [CSCdr91551]

Frame Relay Configuration Problems

Under certain conditions, if you issue the no frame-relay soft-vc dlci, another frame-relay soft-vc on that interface will improperly be deleted. This behavior only applies to IDSL interfaces.

The conditions under which this is known to occur are as follows:

Workaround: Ensure that a valid dlci is specified when you delete a frame-relay soft-vc. [CSCds06327]

Miscellaneous

The following are miscellaneous problems with this release.

Workaround: Use the following CLI commands that display counters:

Loopback and Test Problems

The following are loopback and test problems with this release.

Workaround: Enter the clear interface idsl card/port command to reinitialize the interface. [CSCds01533]

Workaround: Remove and reissue the loopback remote command. [CSCdr62772]

Workaround: Remove and reissue the loopback remote command. [CSCdr63116]

ATM Traffic Shaping and Policing not Functioning

On the Cisco 6160 DSLAM equipped with IDSL line cards, ATM traffic shaping and policing might not function properly. Shaping is enabled on Frame- Relay and PPP PVCs and soft PVCs with the upc drop option of the frame-relay pvc, frame-relay soft-vc, ppp pvc, or ppp soft-vc commands. Policing without traffic shaping (that is, tagging of cells exceeding the ATM traffic descriptor parameters) is enabled with the upc tag option of the above four commands.

Specifically, the following problems are known to exist:

There are no workarounds to the above problems.[CSCdr70582]

Open Caveats—Release 12.1(2)DA

IDSL Line Card Problems

Frame Relay Configuration Problems
Workaround: Power cycle the Motorola Vanguard 65. [CSCdr32145]

Workaround: Explicitly specify the desired setting when you configure Frame Relay soft VCs. [CSCdr62008]

Interface State Problem

On rare occasions, the results of the command show interface idsl slot/port indicate that an interface is up when it is in fact down. You can verify this failure mode by issuing the command show controllers idsl slot/port and confirming that the "C/I" state is not "0xF3".

Workaround: Issue the shutdown command followed by the no shutdown command on the IDSL interface. [CSCdr23602]

Status Display Problems
Loopback and Testing Problems
Workaround: Disable and re-enable the interface using the shutdown command followed by the no shutdown command. [CSCdr60773]

Workaround: To abort BERT before reloading the Cisco 6160, use the dsl test idsl slot/port abort command. [CSCdr62092]

Workaround: Use the no loopback remote command to turn the remote loopback off, then use the loopback remote command to turn it on again. [CSCdr62772]

Workaround: Use the no loopback remote command to turn the remote loopback off, then use the loopback remote command to turn it on again. [CSCdr63116]

SDSL Line Card Problem

In a fully loaded chassis after hours of normal operation, one or more ports of a line card begins to have trickle CRC errors at medium to high data rates. The problem resolves itself upon retrain. [CSCdr46450]

Flexi Line Card Problems

Trellis Coding Disabled Can Cause Errors with Flexi-DMT Cards

We recommend that trellis coding be enabled in this release for the Flexi-DMT line card.


Note   Note: We recommend that you disable trellis coding for ATUC-1-4DMT2 line cards. See the "Trellis Coding Can Cause Errors" section.

Interleave Delay of Zero Can Cause Errors with Flexi-DMT Cards

We recommend that the interleave configuration be set to 1000 microseconds or greater for optimal reach performance. [CSCdr27700]

Line Card Alarms Not Cleared When a Flexi Card Changes Type

When you change a flexi card type from DMT to CAP or CAP to DMT, the active alarms are not cleared.

Workaround: Before you change the line card provisioned mode, clear the existing alarms by issuing shutdown commands to all ports with active alarms. [CSCdr13611]

VCs Are Not Released When a Flexi Card Changes Type

When you change a flexi card type from DMT to CAP or CAP to DMT, the existing virtual channels (VCs) on the interfaces of that card are not deleted; instead they are kept in REMOVED state. Hence you cannot reuse these VCs for the new card type. However, if you change the card type back to the original type, these VCs become available.

Workarounds: Do one of the following:

ATUC-1-4DMT2 Line Card Problems

Training Problems
The effective minimum values depend upon

For the standard training mode, the effective minimum end-to-end margin is 1 to 3 dB. For the quick training mode, the effective minimum end-to-end margin is 4 to 6 dB. The effective margins might be better (that is, at the lower ends of the specified ranges) if interleaving is turned off and/or the bit rates fall between 6 Mbps and 3 Mbps. [CSCdm89068]

4DMT Line Card Reloads Current Code

If the 4DMT line card boot register is set for the card to reload application code, it reloads when the system reboots even if the load image is the same as the code already loaded on the card. (The reload takes about 2 minutes.) This problem occurs only when the system is rebooted; it does not occur when the line card is installed in a chassis. The card should reload only if the version of the load image is different from the version for the code already loaded. [CSCdm64615]

Trellis Coding Can Cause Errors

For ATUC-1-4DMT line cards, we recommend that trellis coding not be enabled in this release. (Trellis coding is disabled by default.)

Although trellis coding works reliably on most loops and most trains, it does not always work reliably. For some trains on some loops, enabling trellis coding causes continuous errored seconds, as well as corrupted data in the upstream direction. It is not possible to predict the circumstances under which this happens. This problem will be fixed in a later release. [CSCdm73343]

Some Combinations of Framing Mode and Bit Rate Cause Data Corruption

Under certain combinations of upstream bit rate and overhead framing mode, no valid data flows upstream. When the line trains at these combinations, data going upstream is corrupted. Avoid these data rate and framing mode combinations:

Upstream Bit Rate Overhead Framing Mode

32 kbps

Mode 1

64 kbps

Mode 2

96 kbps

Mode 3

Workaround: To avoid this data corruption problem, use these combinations of settings for the lower data rates:

Upstream Bit Rate Overhead Framing Mode

32 kbps

Mode 3

64 kbps

Mode 1

96 kbps

Mode 1

[CSCdm66085]

Decreasing Interleaving Delay Increases Errored Seconds

When the DLSAM is connected to a Cisco 676 or any other CPE that is based on ADI's AD20MSP910 chipset (which was designed to support the older Issue 1 version of the T1.413 ADSL standard), you might experience higher than normal numbers of errored seconds, corrected superframes, and uncorrected superframes. This can occur when the interleaving delay is configured at values less than the maximum (16 msec). The errors can occur in both the upstream and downstream directions. This problem might be more apparent with short loop lengths (for example, those less than 4000 feet).

Workarounds: Do either of the following to eliminate the problem:

Check Bytes Are Not Reported Correctly

The value you configure for the check bytes parameter might not be properly reported by the system. An incorrect check bytes value equal to half of the configured value is reported when a port is set to use standard training mode and the downstream data rate is greater than 7 Mbps. Only the downstream path is affected. The actual ratio of user data to check bytes matches the configuration. [CSCdm90741]

Interleaving Delay Is Not Reported Correctly

When a line that is configured for quick training mode trains to a downstream bit rate of 8 Mbps or higher, the actual interleaving delay might be reported incorrectly. (The interleaving delay appears in the display for the command show dsl int atm slot/port.) When this problem occurs, the reported interleaving delay is half of the value that is actually in effect. [CSCdp14712]

DMT Ports Do Not Train Under Some FEC Check Bytes Settings

This applies to the ATUC-1-4DMT2 line card. If a port is configured for standard training mode and the number of FEC check bytes for the downstream direction is configured for 2, 6, 10, or 14, then the port may have trouble staying trained if the loop conditions (such as loop length and noise levels) are favorable for training at a high bitrate. In other words, if the port would otherwise train at or above certain threshold bitrates in the downstream direction, and the FEC check bytes per codeword is set for 2, 6, 10, or 14, then the port continually retrains.

This problem does not occur if any of the following are true:

The threshold bit rates at which this problem appears for each check byte per codeword setting are as follows:

FEC Check Bytes per Codeword Threshold Downstream Bit Rate

0

Problem does not occur

2

8000 Kbps

4

Problem does not occur

6

7872 Kbps

8

Problem does not occur

10

7744 Kbps

12

Problem does not occur

14

7616 Kbps

16

Problem does not occur

Workarounds: Do one of the following:

NI-2 Cannot Recover if Bootflash Image Is Deleted

Xmodem, which resides in rommon on the NI-2 card, is not working. As a result, there is no way to recover if you delete the software image in bootflash and then try to reboot the system. In this case you must replace the NI-2.

Workaround: If you delete the image in bootflash, copy a new image into bootflash before shutting down or rebooting the system. [CSCdr22773]

VPI Values for VP Tunnels Not Checked on Down Interfaces

The software check for invalid VPI numbers on VP tunnels occurs only if the interface associated with the VP tunnel is up. If the interface is down, the system accepts invalid VPI values, but when the interfaces come back up, VPIs are assigned unpredictably. For more information on assigning VPI values, see the "Assigning VPI Values to Shaped VP Tunnels" section.

Workaround: Use a block of 32 consecutive VPI values (for example, 0 to 31 or 101 to 133). Or, if you require a complete range of VPI values, make sure not to configure the VPIs that become unavailable once a VPI is used for a shaped VP tunnel. [CSCdr19173]

Incorrect Margin Value Reported for Some Cisco 678 Connections

When the DSLAM connects to a Cisco 678 CPE running a software version older than CBOS Release 2.3.5, the downstream margin reported is half of the actual margin.

Maximum VCI Bits Value on Subscriber Ports Can Exceed 8

When autoconfiguration is enabled on a subscriber port, the DSLAM might set the maximum VCI bits for that port to an incorrect value that exceeds the maximum allowed value of 8. This depends upon a negotiated value with the connecting port on the adjacent node.

Workaround: Use the command no atm auto-configuration to disable autoconfiguration for subscriber ports. (Autoconfiguration is enabled by default.) [CSCdr18239]

Ignore the Input Queue Field in show Command Output

The input queue field in the output of the show interface atm slot#/port# command is not applicable in the NI-2 environment. Ignore this field. [CSCdp68075]

Ping Command Fails in Extended Command Line

The extended version of the ATM ping command returns "Bad Interface Port" when it is executed on the NI-2. The system accepts the same command in line form, however.

For example, the NI-2 accepts this command:

DSLAM> ping atm int atm 0/1 0 100 atm-prefix 47.00918100000000E01417DA01

If you use the extended command line, however, the same command is rejected:

ping Protocol [ip]: atm Interface [card/port]: 0/1 % Bad Interface Port #

Workaround: Use the line form of the ping atm command. [CSCdr27204]

Problems Affecting Management Systems

These problems affect SNMP-based management systems, including the Cisco DSL Manager (CDM). You can avoid these problems by using the CLI.

Workaround: Use the CLI command subtend-id node# to set or change the subtend ID. [CSCdm93577]

Only CBR Tunnels Are Allowed

The system incorrectly allows you to create VBR-RT and VBR-NRT tunnels. In fact the system can handle only CBR tunnels, and tunnels created as VBR-RT or VBR-NRT behave like CBR tunnels. [CSCdp21731]

Bitswap Command Is Not Functional

The dmt bitswap margin command has no effect in this release. Bit swapping is always disabled. [CSCdm80069]

Virtual Path Deconfiguration Problem

Sometimes it is impossible to remove a configured PVP. When VP switching is configured from one subscriber port to another using the same VPI number on both the ports, the VP circuit is not set up correctly.

Workaround: Configure different VPI numbers on the subscriber ports at either end of the connection. [CSCdp44469]

OAM RDI Cannot Be Enabled

If you create a PVC using network management, the system does not allow you to enable OAM RDI. Regardless of your selection for OAM RDI, the cross connect setting forces the OAM RDI to disable. This is related to the CDM issue CSCdp08324.

Workaround: In CDM, edit the PVC and enable OAM RDI. Or in the CLI, use the interface configuration version of the atm oam rdi command. [CSCdp74861]

ATM Input Queue is Limited to 255 Cells

The maximum size of input queue counter that can be supported by hardware is 255 cells. (You can configure this using the max-size argument of the atm input-queue command.) But software allows configuration of values beyond 255. Limiting input traffic will work only for queue sizes configured 255 cells or less. When you enter a value higher than 255, no input queue function is performed—all traffic is allowed through. [CSCdp25887]

Boot Problem

No matter what you set the configuration register or the bootvar to, rommon always boots up off bootflash.

Workaround: To correct the problem, follow these steps.


Step 1   Add the following command to the startup configuration file: boot system flash flash:filename, where filename is the name of the image to be loaded. For example:

boot system flash flash:ni2-dsl-dmt.120-8.DA

Step 2   To make the system boot correctly, enter these commands, beginning in privileged EXEC mode:

c6260#> configure terminal c6260#> config-register 0x2102

[CSCdp61780]


Open Caveats—Release 12.1(1)DA1

Ethernet Port Cannot Recover Itself

When IP routing is enabled on an NI-2 DSLAM, the Ethernet port 0/0 does not come back up by itself after it experiences a problem. To re-enable the port, enter the shut command in interface configuration mode, then enter the no shut command.

Workarounds: Do one of the following:

NI-2 Cannot Recover if Bootflash Image Is Deleted

Xmodem, which resides in rommon on the NI-2 card, is not working. As a result, there is no way to recover if you delete the software image in bootflash and then try to reboot the system. In this case you must replace the NI-2.

Workaround: If you delete the image in bootflash, copy a new image into bootflash before shutting down or rebooting the system. [CSCdr22773]

VPI Values for VP Tunnels Not Checked on Down Interfaces

The software check for invalid VPI numbers on VP tunnels occurs only if the interface associated with the VP tunnel is up. If the interface is down, the system accepts invalid VPI values, but when the interfaces come back up, VPIs are assigned unpredictably. For more information on assigning VPI values, see the "Assigning VPI Values to Shaped VP Tunnels" section.

Workaround: Use a block of 32 consecutive VPI values (for example, 0 to 31 or 101 to 133). Or, if you require a complete range of VPI values, make sure not to configure the VPIs that become unavailable once a VPI is used for a shaped VP tunnel. [CSCdr19173]

Incorrect Margin Value Reported for Some Cisco 678 Connections

When the DSLAM connects to a Cisco 678 CPE running a software version older than CBOS Release 2.3.5, the downstream margin reported is half of the actual margin.

Maximum VCI Bits Value on Subscriber Ports Can Exceed 8

When autoconfiguration is enabled on a subscriber port, the DSLAM might set the maximum VCI bits for that port to an incorrect value that exceeds the maximum allowed value of 8. This depends upon a negotiated value with the connecting port on the adjacent node.

Workaround: Use the command no atm auto-configuration to disable autoconfiguration for subscriber ports. (Autoconfiguration is enabled by default.) [CSCdr18239]

Ignore the Input Queue Field in show Command Output

The input queue field in the output of the show interface atm slot#/port# command is not applicable in the NI-2 environment. Ignore this field. [CSCdp68075]

DMT Ports Do Not Train Under Some FEC Check Bytes Settings

This applies to the ATUC-1-4DMT2 line card. If a port is configured for standard training mode and the number of FEC check bytes for the downstream direction is configured for 2, 6, 10, or 14, then the port may have trouble staying trained if the loop conditions (such as loop length and noise levels) are favorable for training at a high bitrate. In other words, if the port would otherwise train at or above certain threshold bitrates in the downstream direction, and the FEC check bytes per codeword is set for 2, 6, 10, or 14, then the port continually retrains.

This problem does not occur if any of the following are true:

The threshold bit rates at which this problem appears for each check byte per codeword setting are as follows:

FEC Check Bytes per Codeword Threshold Downstream Bit Rate

0

Problem does not occur

2

8000 Kbps

4

Problem does not occur

6

7872 Kbps

8

Problem does not occur

10

7744 Kbps

12

Problem does not occur

14

7616 Kbps

16

Problem does not occur

Workarounds: Do one of the following:

Ping Command Fails in Extended Command Line

The extended version of the ATM ping command returns "Bad Interface Port" when it is executed on the NI-2. The system accepts the same command in line form, however.

For example, the NI-2 accepts this command:

DSLAM> ping atm int atm 0/1 0 100 atm-prefix 47.00918100000000E01417DA01

If you use the extended command line, however, the same command is rejected:

ping Protocol [ip]: atm Interface [card/port]: 0/1 % Bad Interface Port #

Workaround: Use the line form of the ping atm command. [CSCdr27204]

VCs Are Not Released When a Flexi Card Changes Type

When you change a flexi card type from DMT to CAP or CAP to DMT, the existing virtual channels (VCs) on the interfaces of that card are not deleted; instead they are kept in REMOVED state. Hence you cannot reuse these VCs for the new card type. However, if you change the card type back to the original type, these VCs become available.

Workarounds: Do one of the following:

Problems Affecting Management Systems

These problems affect SNMP-based management systems, including the Cisco DSL Manager (CDM). You can avoid these problems by using the CLI.

Workaround: Use the CLI command subtend-id node# to set or change the subtend ID. [CSCdm93577]

Only CBR Tunnels Are Allowed

The system incorrectly allows you to create VBR-RT and VBR-NRT tunnels. In fact the system can handle only CBR tunnels, and tunnels created as VBR-RT or VBR-NRT behave like CBR tunnels. [CSCdp21731]

Problems Affecting the ATUC-1-4DMT2 Line Card

Training Problems
The effective minimum values depend upon

For the standard training mode, the effective minimum end-to-end margin is 1 to 3 dB. For the quick training mode, the effective minimum end-to-end margin is 4 to 6 dB. The effective margins might be better (that is, at the lower ends of the specified ranges) if interleaving is turned off and/or the bit rates fall between 6 Mbps and 3 Mbps. [CSCdm89068]

Trellis Coding Can Cause Errors

We recommend that trellis coding not be enabled in this release. (Trellis coding is disabled by default.)

Although trellis coding works reliably on most loops and most trains, it does not always work reliably. For some trains on some loops, enabling trellis coding causes continuous errored seconds, as well as corrupted data in the upstream direction. It is not possible to predict the circumstances under which this happens. This problem will be fixed in a later release. [CSCdm73343]

Some Combinations of Framing Mode and Bit Rate Cause Data Corruption

Under certain combinations of upstream bit rate and overhead framing mode, no valid data flows upstream. When the line trains at these combinations, data going upstream is corrupted. Avoid these data rate and framing mode combinations:

Upstream Bit Rate Overhead Framing Mode

32 kbps

Mode 1

64 kbps

Mode 2

96 kbps

Mode 3

Workaround: To avoid this data corruption problem, use these combinations of settings for the lower data rates:

Upstream Bit Rate Overhead Framing Mode

32 kbps

Mode 3

64 kbps

Mode 1

96 kbps

Mode 1

[CSCdm66085]

4DMT Line Card Reloads Current Code

If the 4DMT line card boot register is set for the card to reload application code, it reloads when the system reboots even if the load image is the same as the code already loaded on the card. (The reload takes about 2 minutes.) This problem occurs only when the system is rebooted; it does not occur when the line card is installed in a chassis. The card should reload only if the version of the load image is different from the version for the code already loaded. [CSCdm64615]

Decreasing Interleaving Delay Increases Errored Seconds

When the DLSAM is connected to a Cisco 676 or any other CPE that is based on ADI's AD20MSP910 chipset (which was designed to support the older Issue 1 version of the T1.413 ADSL standard), you might experience higher than normal numbers of errored seconds, corrected superframes, and uncorrected superframes. This can occur when the interleaving delay is configured at values less than the maximum (16 msec). The errors can occur in both the upstream and downstream directions. This problem might be more apparent with short loop lengths (for example, those less than 4000 feet).

Workarounds: Do either of the following to eliminate the problem:

Check Bytes Are Not Reported Correctly

The value you configure for the check bytes parameter might not be properly reported by the system. An incorrect check bytes value equal to half of the configured value is reported when a port is set to use standard training mode and the downstream data rate is greater than 7 Mbps. Only the downstream path is affected. The actual ratio of user data to check bytes matches the configuration. [CSCdm90741]

Interleaving Delay Is Not Reported Correctly

When a line that is configured for quick training mode trains to a downstream bit rate of 8 Mbps or higher, the actual interleaving delay might be reported incorrectly. (The interleaving delay appears in the display for the command show dsl int atm slot/port.) When this problem occurs, the reported interleaving delay is half of the value that is actually in effect. [CSCdp14712]

Bitswap Command Is Not Functional

The dmt bitswap margin command has no effect in this release. Bit swapping is always disabled. [CSCdm80069]

Virtual Path Deconfiguration Problem

Sometimes it is impossible to remove a configured PVP. When VP switching is configured from one subscriber port to another using the same VPI number on both the ports, the VP circuit is not set up correctly.

Workaround: Configure different VPI numbers on the subscriber ports at either end of the connection. [CSCdp44469]

OAM RDI Cannot Be Enabled

If you create a PVC using network management, the system does not allow you to enable OAM RDI. Regardless of your selection for OAM RDI, the cross connect setting forces the OAM RDI to disable. This is related to the CDM issue CSCdp08324.

Workaround: In CDM, edit the PVC and enable OAM RDI. Or in the CLI, use the interface configuration version of the atm oam rdi command. [CSCdp74861]

ATM Input Queue is Limited to 255 Cells

The maximum size of input queue counter that can be supported by hardware is 255 cells. (You can configure this using the max-size argument of the atm input-queue command.) But software allows configuration of values beyond 255. Limiting input traffic will work only for queue sizes configured 255 cells or less. When you enter a value higher than 255, no input queue function is performed—all traffic is allowed through. [CSCdp25887]

Boot Problem

No matter what you set the configuration register or the bootvar to, rommon always boots up off bootflash.

Workaround: To correct the problem, follow these steps.


Step 1   Add the following command to the startup configuration file: boot system flash flash:filename, where filename is the name of the image to be loaded. For example:

boot system flash flash:ni2-dsl-dmt.120-8.DA

Step 2   To make the system boot correctly, enter these commands, beginning in privileged EXEC mode:

c6260#> configure terminal c6260#> config-register 0x2102

[CSCdp61780]


Open Caveats—Release 12.1(1)DA

VPI Values for VP Tunnels Not Checked on Down Interfaces

The software check for invalid VPI numbers on VP tunnels occurs only if the interface associated with the VP tunnel is up. If the interface is down, the system accepts invalid VPI values, but when the interfaces come back up, VPIs are assigned unpredictably. For more information on assigning VPI values, see the "Assigning VPI Values to Shaped VP Tunnels" section.

Workaround: Use a block of 32 consecutive VPI values (for example, 0 to 31 or 101 to 133). Or, if you require a complete range of VPI values, make sure not to configure the VPIs that become unavailable once a VPI is used for a shaped VP tunnel. [CSCdr19173]

Incorrect Margin Value Reported for Some Cisco 678 Connections

When the DSLAM connects to a Cisco 678 CPE running a software version older than CBOS Release 2.3.5, the downstream margin reported is half of the actual margin.

Maximum VCI Bits Value on Subscriber Ports Can Exceed 8

When autoconfiguration is enabled on a subscriber port, the DSLAM might set the maximum VCI bits for that port to an incorrect value that exceeds the maximum allowed value of 8. This depends upon a negotiated value with the connecting port on the adjacent node.

Workaround: Use the command no atm auto-configuration to disable autoconfiguration for subscriber ports. (Autoconfiguration is enabled by default.) [CSCdr18239]

Ignore the Input Queue Field in show Command Output

The input queue field in the output of the show interface atm slot#/port# command is not applicable in the NI-2 environment. Ignore this field. [CSCdp68075]

DMT Ports Do Not Train Under Some FEC Check Bytes Settings

This applies to the ATUC-1-4DMT2 line card. If a port is configured for standard training mode and the number of FEC check bytes for the downstream direction is configured for 2, 6, 10, or 14, then the port may have trouble staying trained if the loop conditions (such as loop length and noise levels) are favorable for training at a high bitrate. In other words, if the port would otherwise train at or above certain threshold bitrates in the downstream direction, and the FEC check bytes per codeword is set for 2, 6, 10, or 14, then the port continually retrains.

This problem does not occur if any of the following are true:

The threshold bit rates at which this problem appears for each check byte per codeword setting are as follows:

FEC Check Bytes per Codeword Threshold Downstream Bit Rate

0

Problem does not occur

2

8000 Kbps

4

Problem does not occur

6

7872 Kbps

8

Problem does not occur

10

7744 Kbps

12

Problem does not occur

14

7616 Kbps

16

Problem does not occur

Workarounds: Do one of the following:

Failed Ports Bring Down Healthy Ports on Same Line Card

When a hardware failure occurs on one or more of the ports on a 4DMT-2 line card, every other (otherwise healthy) port on the line card might be unable to train. Cisco strongly recommends that you replace or remove any line card with any defective ports. [CSCdp05249]

Ping Command Fails in Extended Command Line

The extended version of the ATM ping command returns "Bad Interface Port" when it is executed on the NI-2. The system accepts the same command in line form, however.

For example, the NI-2 accepts this command:

DSLAM> ping atm int atm 0/1 0 100 atm-prefix 47.00918100000000E01417DA01

If you use the extended command line, however, the same command is rejected:

ping Protocol [ip]: atm Interface [card/port]: 0/1 % Bad Interface Port #

Workaround: Use the line form of the ping atm command. [CSCdr27204]

VCs Are Not Released When a Flexi Card Changes Type

When you change a flexi card type from DMT to CAP or CAP to DMT, the existing virtual channels (VCs) on the interfaces of that card are not deleted; instead they are kept in REMOVED state. Hence you cannot reuse these VCs for the new card type. However, if you change the card type back to the original type, these VCs become available.

Workarounds: Do one of the following:

Problems Affecting Management Systems

These problems affect SNMP-based management systems, including the Cisco DSL Manager (CDM). You can avoid these problems by using the CLI.

Workaround: Use the CLI command subtend-id node# to set or change the subtend ID. [CSCdm93577]

Only CBR Tunnels Are Allowed

The system incorrectly allows you to create VBR-RT and VBR-NRT tunnels. In fact the system can handle only CBR tunnels, and tunnels created as VBR-RT or VBR-NRT behave like CBR tunnels. [CSCdp21731]

Problems Affecting the ATUC-1-4DMT2 Line Card

Training Problems
The effective minimum values depend upon

For the standard training mode, the effective minimum end-to-end margin is 1 to 3 dB. For the quick training mode, the effective minimum end-to-end margin is 4 to 6 dB. The effective margins might be better (that is, at the lower ends of the specified ranges) if interleaving is turned off and/or the bit rates fall between 6 Mbps and 3 Mbps. [CSCdm89068]

Trellis Coding Can Cause Errors

We recommend that trellis coding not be enabled in this release. (Trellis coding is disabled by default.)

Although trellis coding works reliably on most loops and most trains, it does not always work reliably. For some trains on some loops, enabling trellis coding causes continuous errored seconds, as well as corrupted data in the upstream direction. It is not possible to predict the circumstances under which this happens. This problem will be fixed in a later release. [CSCdm73343]

Some Combinations of Framing Mode and Bit Rate Cause Data Corruption

Under certain combinations of upstream bit rate and overhead framing mode, no valid data flows upstream. When the line trains at these combinations, data going upstream is corrupted. Avoid these data rate and framing mode combinations:

Upstream Bit Rate Overhead Framing Mode

32 kbps

Mode 1

64 kbps

Mode 2

96 kbps

Mode 3

Workaround: To avoid this data corruption problem, use these combinations of settings for the lower data rates:

Upstream Bit Rate Overhead Framing Mode

32 kbps

Mode 3

64 kbps

Mode 1

96 kbps

Mode 1

[CSCdm66085]

4DMT Line Card Reloads Current Code

If the 4DMT line card boot register is set for the card to reload application code, it reloads when the system reboots even if the load image is the same as the code already loaded on the card. (The reload takes about 2 minutes.) This problem occurs only when the system is rebooted; it does not occur when the line card is installed in a chassis. The card should reload only if the version of the load image is different from the version for the code already loaded. [CSCdm64615]

Decreasing Interleaving Delay Increases Errored Seconds

When the DLSAM is connected to a Cisco 676 or any other CPE that is based on ADI's AD20MSP910 chipset (which was designed to support the older Issue 1 version of the T1.413 ADSL standard), you might experience higher than normal numbers of errored seconds, corrected superframes, and uncorrected superframes. This can occur when the interleaving delay is configured at values less than the maximum (16 msec). The errors can occur in both the upstream and downstream directions. This problem might be more apparent with short loop lengths (for example, those less than 4000 feet).

Workarounds: Do either of the following to eliminate the problem:

Check Bytes Are Not Reported Correctly

The value you configure for the check bytes parameter might not be properly reported by the system. An incorrect check bytes value equal to half of the configured value is reported when a port is set to use standard training mode and the downstream data rate is greater than 7 Mbps. Only the downstream path is affected. The actual ratio of user data to check bytes matches the configuration. [CSCdm90741]

Interleaving Delay Is Not Reported Correctly

When a line that is configured for quick training mode trains to a downstream bit rate of 8 Mbps or higher, the actual interleaving delay might be reported incorrectly. (The interleaving delay appears in the display for the command show dsl int atm slot/port.) When this problem occurs, the reported interleaving delay is half of the value that is actually in effect. [CSCdp14712]

Bitswap Command Is Not Functional

The dmt bitswap margin command has no effect in this release. Bit swapping is always disabled. [CSCdm80069]

Virtual Path Deconfiguration Problem

Sometimes it is impossible to remove a configured PVP. When VP switching is configured from one subscriber port to another using the same VPI number on both the ports, the VP circuit is not set up correctly.

Workaround: Configure different VPI numbers on the subscriber ports at either end of the connection. [CSCdp44469]

OAM RDI Cannot Be Enabled

If you create a PVC using network management, the system does not allow you to enable OAM RDI. Regardless of your selection for OAM RDI, the cross connect setting forces the OAM RDI to disable. This is related to the CDM issue CSCdp08324.

Workaround: In CDM, edit the PVC and enable OAM RDI. Or in the CLI, use the interface configuration version of the atm oam rdi command. [CSCdp74861]

ATM Input Queue is Limited to 255 Cells

The maximum size of input queue counter that can be supported by hardware is 255 cells. (You can configure this using the max-size argument of the atm input-queue command.) But software allows configuration of values beyond 255. Limiting input traffic will work only for queue sizes configured 255 cells or less. When you enter a value higher than 255, no input queue function is performed—all traffic is allowed through. [CSCdp25887]

Boot Problem

No matter what you set the configuration register or the bootvar to, rommon always boots up off bootflash.

Workaround: To correct the problem, follow these steps:


Step 1   Add the following command to the startup configuration file: boot system flash flash:filename, where filename is the name of the image to be loaded. For example:

boot system flash flash:ni2-dsl-dmt.120-8.DA

Step 2   To make the system boot correctly, enter these commands, beginning in privileged EXEC mode:

c6260#> configure terminal c6260#> config-register 0x2102

[CSCdp61780]


Resolved Caveats—Release 12.1(3)DA

The problems listed in Table 4 are fixed in Cisco IOS Release 12.1(3)DA.


Table 3: Problems Resolved in Release 12.1(3)DA
Caveat Number Description

CSCdr66442

A device that is connected to an ITUC-1-8IDSL IDSL interface and that requires a unified network clock might experience CRC errors, because the ITUC-1-8IDSL IDSL interface currently uses a local clock only. Support for using a network clock is planned for a future release.

CSCdr04963

The ITUC-1-8IDSL line card does not achieve theoretically possible downstream throughput for small frames (frames on the order of 64 bytes). The line card does achieve theoretically possible downstream rates for larger frames (frames on the order of 256 bytes and up).

CSCdr67353

The output of the show controllers command for a port that is configured for PPP encapsulation does not show the VPI/VCI that is configured between the NI-2 and the line card for that interface. Instead, it always shows VPI/VCI = 0/0, with all the SAR counters being 0. (The count for number of VCs configured is correct.)

Resolved Caveats—Release 12.1(2)DA

The problems listed in Table 4 are fixed in Cisco IOS Release 12.1(2)DA.


Table 4: Problems Resolved in Release 12.1(2)DA
Caveat Number Description

CSCdp05249

When a hardware failure occurs on one or more of the ports on a 4DMT-2 line card, every other (otherwise healthy) port on the line card might be unable to train. Cisco strongly recommends that you replace or remove any line card with any defective ports.

CSCdr56410

When IP routing is enabled on an NI-2 DSLAM, the Ethernet port 0/0 does not come back up by itself after it experiences a problem.

CSCdm89206

Default ATM traffic descriptors cannot be deleted. When you attempt to delete them through the MIB, the MIB incorrectly indicates that the deletion is successful.

Resolved Caveats—Release 12.1(1)DA1

The problems listed in Table 5 are fixed in Cisco IOS Release 12.1(1)DA1.


Table 5: Problems Resolved in Release 12.1(1)DA1
Caveat Number Description

CSCdr43418

Frames are delayed coming downstream from the NI-2.

CSCdr53955

ILMI does not come up between two subtended nodes. As a result, some traffic is dropped in error.

Resolved Caveats—Release 12.1(1)DA

The problems listed in Table 6 are fixed in Cisco IOS Release 12.1(1)DA.


Table 6: Problems Resolved in Release 12.1(1)DA
Caveat Number Description

CSCdp21747, CSCdp03335

The CLI command for creating soft VPs, atm soft-vp, shows an invalid VPI range, and the MIB allows invalid values to be set. The full range of VPI values, 0 to 255, is now supported.

CSCdp19413

The dmtCodewordSize object does not allow a setting of automatic, as the CLI does.

CSCdm92046

The clear counter command does not consistently return all counter values to zero. This problem is not reproducible.

CSCdp17666

When you execute the shutdown command for a port, the port goes out of service, but Cisco IOS still lists the port's administrative status as UP.

CSCdp00996

Periodically, the system generates a serial management bus cyclic redundancy check (SMBCRC) error message such as this:

%NI2-5-LC_NOTICE:Slot[15] SMBCRC (1 days, 3 hours, 37 minutes, 6 seconds)

These messages are informational only and do not affect performance.

CSCdm66087

DMT lines do not train to upstream bit rates that are multiples of 128 kbps. This applies to both standard training and quick training modes, but only in the upstream direction. If a line is configured with a maximum upstream bit rate that is a multiple of 128 kbps, the best upstream bit rate to which the line can train is 32 kbps less than the configured value.

CSCdm91877

When a port is set to use quick training mode, its symbols per codeword value is sometimes reported as "?" (a question mark). This value is displayed when you enter the show dsl int atm command.

CSCdp18533

The MIB defines the ifAlias (subscriber ID) object as a 64-character field. SNMP truncates the field at 20 characters. This problem is not reproducible.

CSCdp26405

If the BITS plug is configured as the system's timing source, and the BITS clock source fails, an alarm is generated. (This behavior is correct.) However, the alarm is not cleared even after you remove the BITS plug from the valid list of clock sources.

CSCdp63686

The system does not allow you to remove VC/VP configuration parameters from the table, falsely claiming the parameters are in use by a connection. The command that fails is no atm connection-traffic-table-row. This problem is not reproducible.

Related Documentation

The software described in these release notes runs on several Cisco NI-2 DSLAM platforms, including the Cisco 6160, the Cisco 6260, and the Cisco 6130. This section lists hardware documents for each platform and software documents for all the platforms.

Hardware Documentation

This section lists the documents for each NI-2 DSLAM platform. In general, you should use the hardware documentation that was shipped to you with your equipment.

These documents contain hardware information that might be useful to Cisco 6160 users:

These documents contain hardware information that might be useful to Cisco 6260 users:

These documents contain hardware information that might be useful to Cisco 6130 users:

Software Documentation

These documents contain software information for all NI-2 DSLAMs:

In these Cisco ATM software manuals, look for information pertaining to the LightStream 1010, which uses the same software base as the NI-2 DSLAMs:

Cisco Connection Online

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Available 24 hours a day, 7 days a week, CCO provides a wealth of standard and value-added services to Cisco customers and business partners. CCO services include product information, product documentation, software updates, release notes, technical tips, the Bug Navigator, configuration notes, brochures, descriptions of service offerings, and download access to public and authorized files.

CCO serves a wide variety of users through two interfaces that are updated and enhanced simultaneously: a character-based version and a multimedia version that resides on the World Wide Web (WWW). The character-based CCO supports Zmodem, Kermit, Xmodem, FTP, and Internet e-mail, and it is excellent for quick access to information over lower bandwidths. The WWW version of CCO provides richly formatted documents with photographs, figures, graphics, and video, as well as hyperlinks to related information.

You can access CCO in the following ways:

For a copy of CCO's Frequently Asked Questions (FAQ), contact cco-help@cisco.com. For additional information, contact cco-team@cisco.com.


Note   If you are a network administrator and need personal technical assistance with a Cisco product that is under warranty or covered by a maintenance contract, contact the Cisco Technical Assistance Center (TAC) at 800 553-2447, 408 526-7209, or tac@cisco.com. To obtain general information about Cisco Systems, Cisco products, or upgrades, contact 800 553-6387, 408 526-7208, or cs-rep@cisco.com.

Documentation CD-ROM

Cisco documentation and additional literature are available in a CD-ROM package, which ships with your product. The Documentation CD-ROM, a member of the Cisco Connection Family, is updated monthly. Therefore, it might be more current than printed documentation. To order additional copies of the Documentation CD-ROM, contact your local sales representative or call customer service. The CD-ROM package is available as a single package or through an annual subscription. You can also access Cisco documentation on the World Wide Web at http://www.cisco.com, http://www-china.cisco.com, or http://www-europe.cisco.com.

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Posted: Fri Mar 15 05:43:36 PST 2002
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