Release Notes for Cisco IOS Release 12.2(1b)DA1 for Cisco DSLAMS with NI-2

These release notes describe features and caveats in Cisco IOSRelease 12.2(1b)DA1 for the Cisco 6015, Cisco 6160, and Cisco 6260 digital subscriber line access multiplexers (DSLAMs).

Note When you upgrade from Cisco IOS 12.1(5)DA1 or earlier images on the NI-2 card to Release 12.2(1b)DA1, you must format the bootflash on the NI-2 card before loading the 12.2(1b)DA1 dboot image. See the "Update the Image in Bootflash to the 12.2(1b)DA1 dboot Image" section.

System Requirements

New and Changed Information

New Hardware Features in Release 12.2(1b)DA1

New Software Features in Release 12.2(1b)DA1

New Hardware Features in Release 12.2(1b)DA

New Software Features in Release 12.2(1b)DA

NI-2 IP Services

The NI-2 IP Services feature has been extended for Cisco IOS Release 12.2(1b)DA. This feature includes:

MIB Object Enhancements

This feature extends and adds support for various standard and enterprise Management Information Base (MIB) objects and provides MIB interfaces for existing IOS commands.

MIBs New to Cisco NI-2

MIBs Extended on Cisco NI-2

Installation Notes

Update the Image in Bootflash to the 12.2(1b)DA1 dboot Image

When you upgrade from Cisco IOS Release 12.1(5)DA1 or earlier images on the NI-2 card to Release 12.2(1b)DA1, you must reformat the bootflash on the NI-2 card.

Note If you are upgrading from Cisco IOS Release 12.1(6)DA, 12.1(6)DA2, 12.1(7)DA, or 12.1(7)DA3 you do not need to reformat the bootflash. You may skip this section and follow the DSLAM upgrade procedure at the following url:
http://www.cisco.com/univercd/cc/td/doc/product/dsl_prod/ios_dsl/rel122/config/04conf09.htm.

Note Cisco highly recommends that you have console access to the NI-2 card during the upgrade procedure. You can use the console connection to troubleshoot any unexpected events that occur during the upgrade.


	Command	Purpose
Step 1	DSLAM# dir bootflash:	Verify that the bootflash image is ni2-dboot-mz.121-5.da1 or ni2-dboot-mz.121-4.da. If it is neither, go to the "Upgrade the Bootflash Image on the NI-2 Card to the 12.1(5)DA1 dboot Image" section and perform the instructions there, then return to this step.
Step 2	DSLAM#dir flash:	Display the name of the flash file that begins ni2- and use it as filename in Step 3.
Step 3	DSLAM#delete flash:filename	Delete the flash file name found in Step 2. Repeat Step 2 and Step 3 until all files in the flash have been deleted.
Step 4	DSLAM#squeeze flash:	Recover available space in Flash memory.
Step 5	DSLAM#copy tftp://tftpserver:TFTPBOOT/ni2-ds l-mz.122-1b.da1 flash:	Copy the Cisco IOS image from a tftp server to Flash.
Step 6	DSLAM#configure terminal DSLAM (config)#no boot system DSLAM (config)#boot system flash:ni2-dsl-mz.122-1b.da1 DSLAM#end	Enter global configuration mode. Disable the boot from system. Specify the name of the system image to load at start-up. End global configuration mode.
Step 7	DSLAM#copy running-config startup-config	Save your changes to the start-up configuration.
Step 8	DSLAM#reload	Reload the system to upgrade the image.
Step 9	DSLAM#show version	Confirm that the running image is ni2-dsl-mz.122-1b.da1. If it is not, go to Step 5.
Step 10	DSLAM# format bootflash:	Erase all information in bootflash memory. Answer y to all confirm questions. When the DSLAM returns you to the EXEC prompt, bootflash memory is successfully formatted and ready for use. Ensure that the bootflash is 3.8 MB total. If it is not, go to Step 5.
Step 11	DSLAM#copy tftp://tftpserver:TFTPBOOT/ni2-db oot-mz.122-1b.da1 bootflash:	Copy the boot image from a tftp server to the bootflash.
Step 12	DSLAM# reload	Reload the system to upgrade the image.

Upgrade the Bootflash Image on the NI-2 Card to the 12.1(5)DA1 dboot Image

When you upgrade from Release 12.1(3)DA or earlier images on the NI-2 card to Release 12.1(5)DA1, Cisco recommends that you upgrade the bootflash image on the NI-2 card to the 12.1(5)DA1 dboot image. This is a result of a problem (CSCdr89374) in old bootflash images. This defect may cause the flash application image to fail to self-decompress successfully.


	Command	Purpose
Step 1	DSLAM>enable Password: <password> DSLAM#	Enter enable mode. Enter the password. You have entered enable mode when the prompt changes to DSLAM#.
Step 2	DSLAM# delete bootflash:filename	Make room in the bootflash by deleting the name of the current boot image.
Step 3	DSLAM# squeeze bootflash	Recover available space in bootflash using the squeeze bootflash command.
Step 4	DSLAM# copy tftp://[server name] /[directory]/ni2-dboot-mz.121-5.da1 bootflash:	Copy the boot image to the bootflash.
Step 5	DSLAM# show version	Record the current value of the config-register that appears on the last line of the show version display.
Step 6	DSLAM# configure terminal	Enter global configuration mode. You have entered global configuration mode when the prompt changes to DSLAM (config)#.
Step 7	DSLAM(config)# config-register 0	Set the to 0x0000 so that the NI-2 will reboot in the rom monitor.
Step 8	DSLAM(config)# exit	Exit configure terminal mode.
Step 9	DSLAM# copy running-config startup-config	Save the running configuration.
Step 10	DSLAM# reload	Reset the system.
Step 11	rommon> set	If you see BOOTLDR after you enter this command, the image in bootflash is already being used as the bootstrapper; go to Step 15. Otherwise, go to Step 12 and enter the commands in Steps 12 through 14 to force the system to use ni2-dboot-mz.121-5.bin as the bootstrapper.
Step 12	rommon > unset BOOTLDR	Unset BOOTLDR to remove the variable.
Step 13	rommon > sync	Sync to save the state of rommon.
Step 14	rommon > b	When the NI-2 boots, it uses ni2-dboot-mz.121-5da.bin as your bootstrapper.
Step 15	DSLAM# configure terminal	Enter global configuration mode. You have entered global configuration mode when the prompt changes to DSLAM (config)#.
Step 16	DSLAM(config)# config-register value	Set the config-register to the value you recorded in Step 5.
Step 17	DSLAM(config)# exit	Return to enable mode. Go to the "Update the Image in Bootflash to the 12.2(1b)DA1 dboot Image" section.

Limitations and Restrictions

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

Attainable Bit Rate is Conservative on 4xflexi-DMT and 8xDMT

Limitations

Due to line condition variations between trains, the effect of trellis coding, interleave delay, FEC check bytes, and so forth, the attainable bit rate estimate is not always 100 percent accurate. A conservative approach was taken in making the estimate; therefore, in general, you can get a higher rate than what the estimate suggests. For a fast-path scenario, the results should track fairly closely in the downstream and err on the conservative side in the upstream. For an interleave path scenario, the results are highly dependent on configurations.

At a higher reach or where line conditions are not optimal, the effect of having trellis coding, interleave delay, and FEC check bytes can provide for a much higher rate than was estimated (greater than 128 kbps).

Workaround

There is no workaround. The aggregate bit rate calculation is an estimate, which does not accurately model all the line conditions that affect the true attainable bit rate for a given profile. The calculations for aggregate bit rate are performed as follows:

•

The downstream capacity is obtained from the number of Reed-Solomon payload bytes per frame exchanged during line training, that is, the K value. The per-second estimate is then calculated from this K value. An extrapolated margin value is derived from the per-second estimate to make sure that if the line is trained at the estimated rate, it will still have adequate margin.

•

For upstream, unlike downstream, the Reed-Solomon payload bytes per frame is not readily available. Furthermore, unlike downstream, which requires a CPE EOC response to know the downstream margin, the upstream margin is readily available at the CO (upstream margin is measured at CO end). Using this upstream margin and the number of bins utilized for upstream, an estimate of upstream attainable bit rate is made. (The associated DDTS numbers are CSCdv05351 and CSCdv05322.)

Restrictions for NI-2 IP Services

Restricted Layer 3 Services

Cisco IOS Release 12.2(1b)DA1 does not support the following Layer 3 services (or these services are limited, as noted):

•

The maximum number of MPLS/VPN for PPPoA terminations is limited to 25 VPN for PPPoA and 1 VPN for PPPoE.

•

Cisco recommends using a virtual-template for PPPoX termination rather than a dialer interface.

•

The maximum number of subinterfaces under the trunk or subtend(s) ports is limited to 32 to be used for IP termination.

Integrated Routing and Bridging Not Supported

MPLS VPN mapping of RFC 1483 routed sessions must not be confused with Integrated Routing and Bridging (IRB). IRB is not supported by MPLS VPN mapping of RFC 1483 routed sessions.

VPN Interfaces Restricted to Trunk Interfaces

Do not configure subtended interfaces for MPLS VPN services. Only trunk interfaces support MPLS VPN mapping of RFC 1483 routed sessions.

MPLS ATM-Label Switch Router Functionality Not Supported

DSLAMs are not meant for use as MPLS ATM-Label Switch Routers (ATM-LSRs). When designing your network, keep in mind that DSLAMs act only as Label Edge Routers (LER).

Performance Restrictions for MPLS VPN Traffic

MPLS VPN-enabled interfaces do not perform as well as switched VCs. Please take this into consideration when deploying MPLS VPNs in your networks.

Restricted MPLS Features

The following MPLS-related features are not part of MPLS VPN mapping of RFC 1483 routed sessions:

DSL Interface Limitations

In DSLAMs, each DSL interface can support multiple Permanent Virtual Circuits (PVCs), but Cisco recommends that you use one routed MPLS VC if a dynamic routing such as RIP, is used between the CE and the PE.

MPLS VPN Mapping not Supported on the Eight-Port IDSL ITU-C Line Card

Routed termination of IDSL connections is not supported in Cisco IOS Release 12.2(1b)DA1.

Frame Relay PVCs/Soft PVCs on an IDSL Interface

The number of Frame Relay PVCs/Soft PVCs on an IDSL interface is restricted to 1 if you use the default row in frame-relay connection traffic table (FR-CTT).

When upgrading to Cisco IOS Release 12.2(1b)DA1 from previous releases, you must first create a new row in the FR-CTT with the desired CIR value and use the resultant row number during PVCs/Soft PVCs creation. If you do not create a new row, the second FR PVCs/Soft PVCs command is not parsed and installed on the IDSL interface.

Use of a Ring Topology in a DSLAM Subtend Environment to Achieve ATM Trunk Redundancy

Ring topology is achieved when a node in the subtend tree is attached to the ATM access to provide a physical redundant loop. Thus, when the primary ATM access or one of the ATM trunks in the subtend tree fails, the soft permanent virtual circuits (SPVCs) can be dynamically rerouted through the use of private network-network interface (PNNI). See Figure 1.

This redundancy requires the use of SPVCs. If you use permanent virtual circuits (PVCs) or permanent virtual paths (PVPs), redundancy cannot be provided. The use of the SPVCs allows traffic to be rerouted around the failed access point, because SPVCs leverage this feature of PNNI. When the failure occurs, the SPVCs are disconnected and dynamically reconnected across the new path. See Figure 2.

Requirements

If you implement ring topology in a DSLAM subtend to achieve ATM trunk redundancy, the following requirements apply:

•

You must use SPVCs, PNNI, ATM signaling, and Interim Local Management Interface (ILMI) to enable rerouting. PNNI, ATM signaling, and ILMI are enabled by default. Permanent connections such as PVCs and shaped virtual paths (VPs) will not benefit from the redundant link.

•

You must make the redundant link's PNNI administrative weight higher than the PNNI weight of the primary trunk. Once you change the weight of the redundant link, the subtend tree uses this link only if a failure occurs.

Limitations

•

Increase in latency as well as an increase in cell delay variation (CDV) between the cells. Delay-sensitive traffic, such as voice and video, or traffic that is susceptible to jitter, such as constant bit rate (CBR) voice, might be comprised. This technique is best realized for unspecified bit rate (UBR) traffic, such as consumer internet access, where no strict Quality of Service (QoS) objectives are required.

Once the redundant link is active, the following occurrences are potential problems:

•

Greater possibility of increased congestion in the DSLAM ATM switch fabric, which may cause loss of data.

•

When the main link is restored, there is downtime while the path is being rerouted. After the SPVCs are rerouted to the redundant ATM trunk and the original trunk is repaired or brought back into service, you must manually intervene. You must flap (shut/noshut) the subtend port. Because of retries on the current path, you must keep the trunk down until the maximum retry interval expires.

Cisco DSL Manager

If you are using versions of Cisco DSL Manager (CDM) before CDM Release 3.4—from CDM 1.0 to CDM 3.3(3),—do not upgrade the DSLAMs to this new Cisco IOS release.

If you use both the CDM network management application and Cisco IOS command line interface to manage your Cisco DSLAMs, you should be aware of certain configuration and procedural implications. Please refer to the Release Notes for the Cisco DSL Manager, Release 3.4 for this information.

Important Notes

NI-2 IP Services

During system startup, the following protocol warning messages display. You can ignore these messages.

Soft PVC Address Changes upon Upgrade from Release 12.1(4)DA or Earlier

When you upgrade from Cisco IOS Release12.1(4)DA or earlier to Release 12.2(1b)DA1, the default soft PVC addresses on all interfaces change. This only occurs when you upgrade to Release 12.2(1b)DA1 from Release 12.1(4)DA or earlier.

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 might 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.

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 7-foot equipment rack can house four Cisco 6160 chassis, stacked one on top of another. This configuration maximizes the DSL density within a 7-foot rack. However, if space is available or if you are interested in using multiservice capabilities that the chassis will support in the future, We recommend that you install no more than three Cisco 6160 chassis within a 7-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.

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

Caveats describe unexpected behavior in Cisco IOS software releases. Severity 1 caveats are the most serious caveats; severity 2 caveats are less serious. Severity 3 caveats are moderate caveats, and only select severity 3 caveats are included in the caveats document.

This section contains only open and resolved caveats for the current Cisco IOS release.

Caveat numbers and brief descriptions are listed in Table 1, Table 2, and Table 3. For details about a particular caveat and for information on caveats in previous Cisco IOS releases that also apply to this release, go to Bug Toolkit at:

To access this location, you must have an account on Cisco.com. If you have forgotten or lost your account information, e-mail the Contact Database Administration group at cdbadmin@cisco.com. If you do not have an account on Cisco.com, go to http://www.cisco.com/register and follow the directions to set up an account.

Note If you have an account with Cisco.com, you can use Bug Navigator II to find caveats of any severity for any release. To reach Bug Navigator II, go to Cisco.com and press Login. Then go to Software Center: Cisco IOS Software: Cisco Bugtool Navigator II. Another option is to go to:

http://www.cisco.com/cgi-bin/Support/Bugtool/launch_bugtool.pl.

This software release is based on Cisco IOS Release 12.2. For information on caveats in Cisco IOS Release 12.2, see Caveats for Cisco IOS Release 12.2, which lists severity 1 and 2 caveats and select severity 3 caveats for Cisco IOS Release 12.2 and is located on Cisco.com and the Documentation CD-ROM.

Open Caveats—Release 12.2(1b)DA

All the caveats listed in Table 1 are open in Cisco IOS Release 12.2(1b)DA. This table lists only severity 1 and 2 caveats and select severity 3 caveats.

Table 1 Open Caveats for Cisco IOS Release 12.2(1b)DA
Caveat Number	Description
CSCdt27044	Filesys space error is displayed when performing the first write mem following a reload. Workaround: None. If write mem is issued again, there will not be any error.
CSCdt81452	PPP negotiation would not occur if the ppp encapsulation command references a nonexistent virtual-template. Workaround: Configure a complete virtual-template interface first, then configure the PPP PVC.
CSCdt89256	Cisco 6160 does not recognize the debug atm oam command. Workaround: Use debug atm oam-all to implement the debug functionality.
CSCdt97737	Issuing the debug atm errors command shows an encapsulation error No VC for address. Workaround: None. The system behaves normally.
CSCdu09877	The 8xDMT line card ignores interleave setting when trained to 677. Workaround: None.
CSCdu10692	If you configure no ip cef and ip cef in very quick succession, MPLS will cease operating and the show mpls forwarding command will report that Tag switching is not operational. CEF or tag switching has not been enabled. Workaround: Configure no ip cef, wait 2 seconds and then configure ip cef.
CSCdu21884	No compliant cells are seen while doing VP shaping under 4 Mb. Workaround: Increase PCR rate to greater than 4 Mb, or disable VP shaping. Note Noncompliant cells will be dropped at the next hop.
CSCdu25687	No PPPoA connectivity into MPLS/VPN if a numbered virtual template is used. Workaround: Always use an unnumbered IP address when defining a virtual-template interface. Because a virtual template is used to create virtual accesses, a virtual template should always be created with a unnumbered IP address.
CSCdu35160	Packet loss occurs when policing with abr for MCR values greater than 18. Workaround: None.
CSCdu39970	A per-user route from a previous IPCP Subnet negotiation may appear in the routing table after the PPP circuit has been added again with a no pvc X/Y command and then followed by the pvc X/Y command. Workaround: Use the no ip route command to remove the stale per-user route.
CSCdu40049	Simultaneously adding/deleting dsl-profile causes system reload. Workaround: Avoid doing simultaneous configuration edits from multiple telnet sessions. Cisco recommends that while a session is editing configuration, any other telnet sessions should refrain from manipulating the configuration at the same time.
CSCdu46804	IP Address negotiation via IPCP to an external DHCP Server across an ATM link fails. Workaround: Use a local DHCP server connected on the Ethernet segment.
CSCdu06659	GETNEXT fails for all entries in cAdslAtucDmtChanTable. Workaround: Walk the table manually using a series of snmpgetnext commands.
CSCdu06678	GETNEXT fails for all entries in cAdslAturDmtChanTable. Workaround: Walk the table manually using a series of snmpgetnext commands.
CSCdu74113	Using NAS-PORT format D, the underscore delimiter is missing in the Acct-Session-Id attribute. Workaround: None.
CSCdu78386	The static VRF route applied on the PE does not take effect. There is no connectivity using static routing over MPLS/VPN. Workaround: Redistribute static or RIP route into BGP from the egress PE, thus the ingress PE will learn the egress PE VPN routes.
CSCdv05322	Attainable bit rate is conservative for 4xFLEXI-DMT. Workaround: None. The aggregate bit rate calculation is an estimate, which does not accurately model all the line conditions that affect the true attainable bit rate for a given profile.
CSCdv05351	Attainable bit rate is conservative for 8xDMT. Workaround: None. The aggregate bit rate calculation is an estimate, which does not accurately model all the line conditions that affect the true attainable bit rate for a given profile.

Resolved Caveats—Release 12.2(1b)DA1

Resolved Caveats—Release 12.2(1b)DA

Table 2 Caveats Resolved in Cisco IOS Release 12.2(1b)DA1
Caveat Number	Description
CSCdw65903	An error can occur with management protocol processing. Please use the following URL for further information: http://www.cisco.com/cgi-bin/bugtool/onebug.pl?bugid=CSCdw65903

Table 3 Caveats Resolved in Cisco IOS Release 12.2(1b)DA
Caveat Number	Description
CSCdr38060	Add attainable bit rate on 4xflexi DMT.
CSCdr96185	When executing a show version command, SHDSL ports are shown as SDSL ports.
CSCds14884	No log event link-status command has no effect.
CSCds15469	IP MTU or Physical MTU setting has no effect on fragmentation.
CSCds80863	MIB adslAtucCurrStatus returns incorrect value for CAP and DMT.
CSCds81122	MIB adslAturCurrStatus returns incorrect value for DMT
CSCdt11375	Performance interval counters are not correct for G.SHDSL.
CSCdt34090	Profile created from altered default has different parameters.
CSCdt71353	Minimum DMT bitrate setting is lost after upgrade.
CSCdt73955	The delay does not change when changing oamLoopbackPingDelay.
CSCdt75675	Link down traps are not reliably sent for IDSL.
CSCdt76848	SDSL profile lists rates of 1552, 2064, 2320 and allows their use
CSCdt79352	MIB adslAturChanTransmittedBlks has a MIB value of 0 while CLI has non-0.
CSCdt79387	adslAturVendorID will return 0 from MIB, CLI has 57 (Globespan).
CSCdt79394	MIB adslAtucChanCrcBlockLength always has a value of 0.
CSCdt79405	MIB adslAturChanCrcBlockLength always has a value of 0.
CSCdt79412	MIB cIdslItucInvSerialNumber returns garbage instead of empty string.
CSCdt81887	IMA Group collapses when differential delay changed on one line.
CSCdt88209	Some DSL statistics missing in Cisco IOS 12.1(5)DA for DMT cards.
CSCdt94063	OAM ping of IMA group depends on state of CPE connection.
CSCdu05779	MIB imaGroupLeastDelayLink is not supported in MIB.
CSCdu06348	SDSL attempts to report LOS events instead of LOSQ in show dsl interface.
CSCdu07798	PEM alarm does not clear after hot swap replacement.
CSCdu11030	MIB imaGroupTestProStatus does not match CLI.
CSCdu11335	MIB: All Prev1Day performance counters are always zero.
CSCdu11634	Line ports reset when CPU usage is high.
CSCdu12291	Issuing show run on the NI-2 results in SNMP query timeout.
CSCdu17619	Attainable Aggregate Bitrates do not apply to 8xDMT.
CSCdu20810	CPU utilization is degrading.
CSCdu26649	MIB sonet physical layer does not match logical layer.
CSCdu35353	Limitation to 32 VPI values even if the VP tunnels are not shaped.
CSCdu44511	8xDMT is unable to train at 1024 kbps upstream with Cisco 678.
CSCdu45628	IOS reloads with update_the_1day_counts on top of stack.
CSCdu47978	Init Event counters toggle between 0 and max int in 8xDMT cards.
CSCdu48059	Inconsistent counter operations exist for Atuc/Atur IntervalEntry fields.
CSCdu57284	ItucIntervalNumber is more than 96 while querying ItucIntervalTable.
CSCdu64006	Soft PVC address on 6260 is changed after upgrade.
CSCdu71803	When an F4 OAM atm seg cell, with PT field is set for end-to-end type, is received on nonprovisioned VP, the system reloads.

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