Table of Contents

Configuring Line Card Elements

Enabling and Disabling a Port
Assigning Port Names
Assigning Circuit IDs
Displaying Debugging Information for a Port
Configuring a Slot

Using DSL Profiles

Creating, Modifying, or Deleting a Profile
Copying a Profile
Attaching or Detaching a Profile
Displaying a Profile

Setting DSL Profile Parameters

Enabling and Disabling Alarms
Enabling and Disabling LinkUp/Down Traps
Enabling and Disabling Payload Scrambling
Setting CAP Upstream and Downstream Baud Rate Margins
Setting Upstream and Downstream Bit Rates

Setting Bit Rate Parameters for ATU-C CAP Interfaces
Setting Bit Rate Parameters for DMT Interfaces
Setting DMT Minrate Blocking

Setting Bit Rate Parameters for STU-C Interfaces
Setting Bit Rate Parameters for SHTU-C Interfaces
Setting Signal-to-Noise Ratio Margins

ATU-C CAP and ATU-C Flexi CAP Interfaces
ATU-C 4DMT and 8xDMT Interfaces
SHTU-C Interfaces

Monitoring Signal-to-Noise Ratio
Setting DMT Power-Management-Additional-Margin
Setting the Interleaving Delay

DMT Interfaces
CAP Interfaces

Setting the Number of Symbols per Reed-Solomon Codeword
Setting FEC Check (Redundancy) Bytes
Enabling and Disabling Trellis Coding
Setting the Overhead Framing Mode
Modifying the Operating Mode
Modifying the DMT Training Mode
Modifying the G.SHDSL Training Mode
Setting the Power Spectral Density Mask for ATU-C CAP and ATU-C flexi CAP

Defaults

Setting the Power Spectral Density Mask for SHTU-C
Setting SHTU-C Annex
Setting the ATU-C CAP CPE-Signature

Enabling and Disabling ATM Local Loopback
Displaying DSL and ATM Status
Displaying Hardware Information

Configuring Digital Subscriber Lines

This chapter describes how to configure Cisco digital subscriber line access multiplexers (DSLAMs) with NI-2 for digital subscriber line (DSL) service. The chapter contains the following sections:

• Configuring Line Card Elements
  
  
• Using DSL Profiles
  
  
• Setting DSL Profile Parameters
  
  
• Enabling and Disabling ATM Local Loopback
  
  
• Displaying DSL and ATM Status
  
  
• Displaying Hardware Information
  
  

Configuring Line Card Elements

The following sections discuss configuring ports and slots on line cards:

• Enabling and Disabling a Port
  
  
• Assigning Port Names
  
  
• Assigning Circuit IDs
  
  
• Displaying Debugging Information for a Port
  
  
• Configuring a Slot
  
  

Enabling and Disabling a Port

This section describes how to enable or disable a port.

To enable a port, follow these steps:

To disable a port, follow these steps:

Example

This example enables port 1 on slot 20 and displays the results:

Note   The admin status is modified by the shutdown and no shutdown commands. The oper (operational) status is a function of the ATM switch fabric and the DSL line state.

Assigning Port Names

This section describes how to assign a name to a DSL subscriber port. The name can contain up to 64 printable characters. Alphanumerics and most special characters (underscores, hyphens, and ampersands, for example) are allowed. Spaces and quotes are not allowed.

To assign a name to a DSL subscriber port, follow these steps:

Example

In this example, the name "curley" is assigned to slot 9, port 2.

Assigning Circuit IDs

This section describes how to assign an identifier to a DSL circuit. The circuit ID may contain up to 32 printable characters. Alphanumerics and most special characters (underscores, hyphens, and ampersands, for example) are allowed. Spaces and quotes are not allowed.

To assign an identifier to a DSL circuit, follow these steps:

Example

In this example, the circuit ID 341 is assigned to slot 9, port 2.

Displaying Debugging Information for a Port

This section describes how to display debugging information for a port.

To display debugging information for a port, follow this step:

The output for this command varies with the interface type. It provides low level diagnostic information specific to the physical layer chipset.

Command output for a DMT interface, for example, includes these items:

• Absolute signal-to-noise ratio (SNR) for each of the upstream bins.
  
  
• Bit allocation for each of the upstream and downstream bins.
  
  

---

Note   Output items for SDSL and SHDSL ports will display one value for both upstream and downstream.

---

• Downstream transmit power boost (power spectral density mask, config, and actual). Autoconfigured power boost displays as a whole number of decibels. Actual power boost displays in decibels to one decimal place (0.1 dB) accuracy.
  
  
• The contents of the configuration management variables (CMV) for 4xDMT line cards:
  
  

Example

In this example, the command displays debugging information for ATM 0/1 and ATM 5/2:

Configuring a Slot

To configure a slot for a specific card type, use these commands:

The slot number range varies by platform; the maximum range is 1 to 38. These card types are available:

• ATUC-1-4DMT—4-port DMT card
  
  
• ATUC-1-4DMT-I—4-port DMT over ISDN card
  
  
• ATUC-1-DMT8—8-port DMT card
  
  
• ATUC-1-DMT8-I—8-port DMT over ISDN card
  
  
• ATUC-4FLEXICAP—4-port flexi card configured as CAP
  
  
• ATUC-4FLEXIDMT—4-port flexi card configured as DMT
  
  
• ATUC-8-DMT-1-H—8-port DMT OSP card
  
  
• ITUC-1-8IDSL—8-port IDSL card
  
  
• STUC-4-2B1Q-DIR-1—4-port SDSL card
  
  
• STUC-8-TCPAM—8-port G.SHDSL card
  
  

---

Note   Some line cards do not function in all NI-2 DSLAM systems. Consult the hardware documentation for your DSLAM to determine which line cards it supports.

---

Example

This example configures slot 12 for a 4-port SDSL card and displays the hardware associated with the slot.

If the detected card type matches the slot provisioning for ATU-C or STU-C, the respective card type is displayed. When a provisioned slot is empty or does not match the slot provisioning, the word "Missing" is displayed.

Note   If you attempt to provision an empty slot, the major alarm "Provisioned slot is empty" is asserted.

Intermixing Line Cards

The line coding used by the 4-port flexi line card is spectrally incompatible with the line coding for both the 8-port IDSL line card and the 4-port SDSL (STU-C) line card. If you install spectrally incompatible cards in the same half of the chassis, the lines served by those cards can suffer reduced performance.

The 8xDMT line card is not spectrally compatible with SDSL or IDSL. Place these cards in a separate chassis half when using them in the same chassis as 8xDMT line cards. For best performance in a chassis with a mixture of line card types, always install flexi or 8xDMT cards in one half of the chassis and install IDSL and SDSL cards on the opposite side.

In the Cisco 6160 and Cisco 6260 chassis, you can mix DMT line cards and G.SHDSL line cards by chassis quadrant instead of chassis half. You can mix the 4xDMT, 4xFlexi DMT, and 8xDMT cards in the same quadrant. For example, you can install 24 DMT cards in quadrants 1, 2, and 3 and 6 G.SHDSL cards in quadrant 4.

Note   See the hardware installation guide for your specific DSLAM system for more detailed information about line card intermixing.

Errors

Card mismatch error conditions occur under the following circumstances:

• If a line card of a different type is already installed in the named slot
  
  
• If you provision a slot for one type of card and insert another type of card into the named slot
  
  

---

Note   You must provision an ATU-C flexi for CAP or DMT line coding before it will operate.

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Using DSL Profiles

The following sections discuss using the DSL profiles:

• Creating, Modifying, or Deleting a Profile
  
  
• Copying a Profile
  
  
• Attaching or Detaching a Profile
  
  
• Displaying a Profile
  
  

With the exception of a few dynamic operational modes, port configuration takes place through a configuration profile rather than by direct configuration. A profile is a named list of configuration parameters with a value assigned to each parameter. You can change the value of each parameter in the profile. To configure a subscriber, you need only attach the desired profile to that subscriber. When you change a parameter in a profile you change the value of that parameter on all ports using that profile. If you want to change a single port or a subset of ports, you can copy the profile, change the desired parameters, and then assign the new profile to the desired ports.

Note   If you modify an existing profile, that change takes effect on every asymmetric digital subscriber line (ADSL) port linked to that profile.

This profile configuration approach is consistent with ADSL management information base (MIB) standards.

The DSLAM implementation uses the dynamic profile approach as opposed to the static profile approach. The dynamic profile approach supports a many-to-one correspondence between ports and profiles; that is, multiple ports can share the same profile but not vice versa. Also, with the dynamic approach, profiles are created and destroyed dynamically (with the exception of a special profile named "default"). Direct configuration of port parameters is not allowed.

Note   When you create a profile, it inherits all of the configuration settings of the special profile named "default" at the time of creation. If you subsequently modify the special profile "default," the changes do not propagate to profiles created by the original default profile.

Using profiles introduces a new command mode, profile mode. Use the command dsl-profile to enter profile mode. When you are in profile mode, changes you make to parameters affect only the profile you specify.

The following example sets the interleaved forward error correction (FEC) check bytes for a profile named "test" to 6 upstream and 4 downstream. Other profiles do not change:

Creating, Modifying, or Deleting a Profile

This section describes how to create or delete a profile, and how to select a profile for modification.

To create a profile, or to select a profile for modification, follow these steps:

To delete a profile, follow these steps:

Examples

The following example creates a DSL profile named "fast2." After you execute these steps, you can modify the parameters for this profile:

Copying a Profile

To copy a profile to an identical profile with a different name, follow these steps:

If the destination profile indicated in this command does not exist, dsl-copy-profile creates it. The command then copies all nondefault configurations defined for the source profile to the destination profile.

Example

This example copies the default profile to a profile named "fast" and displays the results. If "fast" does not exist, the command creates it. Use the command show dsl profile to confirm the existence and parameters for the new profile:

Attaching or Detaching a Profile

This section describes how to attach a profile to or detach a profile from a slot or port.

To attach a profile from a slot or port, follow these steps:

To detach a profile from a slot or port, follow these steps:

Example

This example attaches the profile "test1" to slot 20, port 1, and displays the results:

Displaying a Profile

To display a profile and all the ports currently connected to it, complete the following task:

Note   If you omit the profile-name argument, this command displays profile information for all existing DSL profiles.

Example

This example displays the profile "fast":

Setting DSL Profile Parameters

The following sections describe the various parameters that can be set within a DSL profile:

• Enabling and Disabling Alarms
  
  
• Enabling and Disabling LinkUp/Down Traps
  
  
• Enabling and Disabling Payload Scrambling
  
  
• Setting CAP Upstream and Downstream Baud Rate Margins
  
  
• Setting Upstream and Downstream Bit Rates
  
  
• Setting Bit Rate Parameters for STU-C Interfaces
  
  
• Setting Bit Rate Parameters for SHTU-C Interfaces
  
  
• Setting Signal-to-Noise Ratio Margins
  
  
• Setting DMT Power-Management-Additional-Margin
  
  
• Monitoring Signal-to-Noise Ratio
  
  
• Setting the Interleaving Delay
  
  
• Setting the Number of Symbols per Reed-Solomon Codeword
  
  
• Setting FEC Check (Redundancy) Bytes
  
  
• Enabling and Disabling Trellis Coding
  
  
• Setting the Overhead Framing Mode
  
  
• Modifying the Operating Mode
  
  
• Modifying the DMT Training Mode
  
  
• Modifying the G.SHDSL Training Mode
  
  
• Setting the Power Spectral Density Mask for ATU-C CAP and ATU-C flexi CAP
  
  
• Setting the Power Spectral Density Mask for SHTU-C
  
  
• Setting SHTU-C Annex
  
  
• Setting the ATU-C CAP CPE-Signature
  
  

Enabling and Disabling Alarms

You can enable and disable alarms for a selected DSL profile using a single command. The alarms apply to these event classes:

• Near End LOS (loss of signal)
  
  
• Near End LOCD (loss of cell delineation)
  
  
• Near End LOF (loss of frame)
  
  
• ATU-C DMT port failure
  
  
• Up or downstream bit rate not above minimum bit rate
  
  

DSL alarms are disabled by default.

To enable DSL alarms, follow these steps:

To disable DSL alarms, follow these steps:

Example

This example enables alarms for the default profile and displays the results:

Enabling and Disabling LinkUp/Down Traps

You can enable and disable linkUp/Down traps for a selected DSL profile using a single command. The linkUp/Down traps are generated only when the global configuration, the profile configuration and the interface level configuration are all enabled. The traps are disabled on a profile by default.

To enable the linkUp/Down traps follow these steps:

To disable the linkUp/Down traps, follow these steps:

Example

This example enables linkUp/Down traps for the default profile and displays the results:

Enabling and Disabling Payload Scrambling

This section describes how to enable and disable cell payload scrambling on a DMT subscriber port. Payload scrambling is enabled by default.

To disable payload scrambling, complete the following steps:

To enable payload scrambling, complete the following steps:

The two ends of a connection must have the same payload scrambling value—that is, payload scrambling must be enabled at both ends or disabled at both ends. Otherwise, the line does not train.

Enabling or disabling payload scrambling does not cause the port to retrain.

Setting CAP Upstream and Downstream Baud Rate Margins

This section describes how to configure upstream and downstream baud rate margins for ATU-C CAP, and ATU-C flexi CAP interfaces.

Cisco IOS supports provisioning additional baud rates for interface line codes. The following rules apply:

• Valid rate, Cisco IOS selects a rate less than or equal to the rate that you specified.
  
  
• Invalid rate, Cisco IOS modifies the rate to the closest available rate that is less than or equal to the rate that you specified.
  
  

In addition to the existing upstream 136 kilobaud rate, Cisco IOS also supports an upstream 17 kilobaud rate and an upstream 68 kilobaud rate. You can independently enable or disable the new baud rates.

The following list contains the valid upstream/downstream pairs within the available rates:

• An upstream rate of 17 kilobaud is valid only with a downstream rate of 136 kilobaud.
  
  
• An upstream rate of 68 kilobaud is valid only with a downstream rate of 136 kilobaud or a downstream rate of 340 kilobaud.
  
  
• All other combinations are valid.
  
  

Table 4-1 and Table 4-2 show the upstream and downstream baud rates and their corresponding bit rates for the ATU-C CAP and ATU-C flexi CAP interfaces.

The following information applies to Table 4-1 and Table 4-2:

• Enabling 17 kilobaud upstream and 68 kilobaud upstream rates are not mutually exclusive.
  
  
• The valid upstream rates are the union of the common rates (136 kilobaud upstream) and the bit rates corresponding to the new bauds (17 kilobaud upstream and 68 kilobaud upstream).
  
  
• If a given upstream rate appears in more than one selected baud rate list, the higher baud rate applies.
  
  

To enable baud rates, follow these steps:

To disable baud rates, follow these steps:

Setting Upstream and Downstream Bit Rates

This section describes how to configure upstream and downstream bit rates for ATU-C CAP and ATU-C flexi CAP, DMT, STU-C, and SHTU-C interfaces.

Setting Bit Rate Parameters for ATU-C CAP Interfaces

To set the downstream and upstream minimum or maximum bit rates for a CAP interface, follow these steps:

To return the downstream and upstream bit rates for a CAP interface to their default values, follow these steps:

Defaults

The following list shows the defaults for minimum and maximum downstream and upstream bit rates for the ATU-C CAP interface.

The alarm subsystem uses the minimum bit rate settings. Cisco IOS software asserts an alarm if the line card trains at a rate below the configured minimum bit rate.

Examples

In this example, the command sets the maximum downstream and upstream bit rates to 7168 kbps, and 1088 kbps, respectively:

In this example, the command sets the maximum downstream and upstream bit rates to the default values for that particular interface. In this case, it is a quad-port ATU-C flexi CAP.

Setting Bit Rate Parameters for DMT Interfaces

To set the maximum allowed bit rate for interleaved-path DMT parameters for a specific profile, follow these steps:

To set the minimum allowed bit rate for interleaved-path DMT parameters for a specific profile, follow these steps:

The Cisco IOS software does not send minimum bit rate settings to the line card. The software uses these settings locally to determine if a line rate alarm should be set for a port.

Setting the DMT minimum bit rate to 0 disables the associated minimum DMT bit rate alarm.

Table 4-3 lists the allowable ranges and default values for DMT bit rate.

Caution   The dmt bitrate command causes the port to retrain when you change the value of the bit rate parameter.

If you set a parameter to its current value, the port does not retrain. If a port is training when you change the parameter, the port stops training and retrains to the new parameter.

Example

This example sets the maximum interleaved path bit rate of the default profile to 640 kbps downstream and 128 kbps upstream, and displays the results:

In this example, the command sets the maximum fast bit rate of the default profile to 3200 kbps downstream and 640 kbps upstream:

Setting DMT Minrate Blocking

To specify the bit rate below which a DMT port does not retrain, use the dmt minrate-blocking command.

Setting Bit Rate Parameters for STU-C Interfaces

To set the bit rate for STU-C parameters for a profile, follow these steps:

Example

In this example, the command sets the bit rate of the default profile to 528 kbps downstream and upstream:

The Cisco IOS software does not send minimum bit rate settings to the STU-C line card. The software uses the settings locally to determine if a line rate alarm should be set for a port.

The following allowable STU-C bit rate values occur in units of kilobits per second:

2320

2064

1552

1168

1040

784

528

400

272

144

Caution   The sdsl bitrate bitrate command causes the port to retrain when you change the parameter.

Setting a parameter to its current value does not cause a retrain. If a port is training when you change the parameter, the port untrains and retrains to the new parameter value.

Setting Bit Rate Parameters for SHTU-C Interfaces

To set the bit rate for SHTU-C parameters for a profile, use the following procedure that modifies the default bit rate parameters in your DSL profile:

Example

The following example shows how to use the shdsl bitrate command to configure the upstream and downstream bandwidth at 2312 kbps:

Setting Signal-to-Noise Ratio Margins

This section describes how to set signal-to-noise ratio (SNR) margins for both downstream and upstream traffic for ATU-C CAP, ATU-C flexi CAP, ATU-C flexi DMT, 4xDMT, and SHTU-C interfaces. The higher the SNR margin the more protection there is against data corruption. The higher the SNR margin the lower the data rate a given loop can support.

ATU-C CAP and ATU-C Flexi CAP Interfaces

Use the following profile configuration commands to set the SNR value for a selected ATU-C CAP or ATU-C flexi CAP profile:

To set the SNR margin values for an ATU-C CAP interface to the default values of 3 dB downstream and 6 dB upstream, follow these steps:

Example

In this example, the command sets the SNR margin at 8 dB downstream and 5 dB upstream for the DSL "issis" profile:

ATU-C 4DMT and 8xDMT Interfaces

The range of DMT margin values is 0 to 15 dB in each direction. The default value for each direction is 6 dB.

To set SNR margins for a 4xDMT or 8xDMT interface, follow these steps:

This command retrains the port if you change the parameter value. Setting a parameter to its previous value does not cause a retrain. If a port is training when you change this parameter, the port untrains and retrains to the new parameter value.

Example

This example sets the SNR margins of the default profile to 6 dB upstream and 6 dB downstream and displays the results:

SHTU-C Interfaces

You can set SNR margins for minimum, target, and threshold on selected SHTU-C profiles.

• Target—In rate adaptive mode, the target margin determines the amount of margin required before the line trains. If the line cannot achieve the target margin it attempts to train at a lower rate. The line continues to lower the rate until it finds a line rate that supports the target margin.
  
  
• Min—Configures the minimum SNR margin for the selected DSL profile. If the SNR falls below the configured value after the line has trained for 5 seconds, the line drops and attempts to retrain.
  
  
• Threshold—Configures the minimum SNR threshold margin. If the SNR margin falls below the configured value, an SNR margin threshold alarm is issued.
  
  

To set SNR margins for an 8xG.SHDSL interface, follow these steps:

Example

The following example shows you how to configure the shdsl margin values min 2, threshold 10, and target 0:

Monitoring Signal-to-Noise Ratio

DMT rate adaptation monitors upstream and downstream DMT ports for signal-to-noise ratio (SNR) margins during specified time intervals. If an unacceptable SNR margin is detected, the port is retrained at a lower bit rate to improve the SNR margins. To change the intervals during which a DMT port is monitored for signal-to-noise ratio (SNR) margins, use the dmt rate adaptation interval command in DSL profile configuration mode.

Example

The following example enables dmt rate-adaptation with default interval and margin values:

Setting DMT Power-Management-Additional-Margin

Often, the capacity of a customer line is greater than the data rate of the customer service. This situation generally manifests itself as an SNR margin that is in excess of the target margin. In such a case, you should reduce the excess margin and bring it closer to the target margin, by reducing power. Power cutback is desirable for both a reduction in power dissipation and a reduction in cross talk.

The 8xDMT line card can run in power-management mode in the G.dmt or the T1.413 mode. Only 8xDMT line cards support power management. All CPE may not support the DSL functionality for power management to function correctly. Check with a Cisco customer representative to verify CPE compatibility with the 8xDMT power management.

You control the Power Management feature by issuing a dmt power-management-additional-margin command inside a profile and assigning that profile to a line card interface. This IOS command allows you to set the additional margin for each channel from 0 dB (off) to 15 dB. This sets the additional margin that will be added to the target margin. If the sum of the target margin and additional margin exceeds 15dB, it is capped at 15dB. If the actual margin of the line is higher than the sum of the configured target and additional margin, then power management attempts to reduce the actual margin, and as a consequence the power level as well.

Not all CPE support power management. If you connect an unsupported CPE to a port on which power management is turned on, you will not see a reduction in the actual margin or power level. The operating modes supported by power management are T1.413and g-992-1 (g.dmt). A reduction in the power level occurs if there is excess margin on the line. For the downstream direction, if there is excess margin, then IOS displays a reduction in margin for the modes listed above, and a reduction in transmit power for T1.413 mode. For the upstream direction, if there is excess margin, then IOS displays a reduction in the margin for g-992-1 mode only. IOS will not display a reduction in transmit power for the upstream direction.

To set power management mode for a DMT profile, use the dmt power-management-additional-margin command.

Example

In the following example, power management would begin at 9 dB because the original margin is 6 dB and the additional margin is 3 dB:

Setting the Interleaving Delay

This section describes how to set the interleaving delay for both the upstream and downstream traffic for DMT and CAP interfaces.

If possible, the DSLAM sets the actual interleaving delays to match the values configured in the profile. However, depending upon the bit rate to which the port finally trains, some settings of interleaving delay may not be achievable. In this case, the DSLAM chooses an actual interleaving delay that is closest (numerically) to the configured interleaving delay. Table 4-4 lists the values of interleaving delay that are achievable for all bit rates.

DMT Interfaces

Interleaving delay helps protect against impulse noise and clipping, but adds delay, which might not be tolerable for some applications.

The allowable values for configured interleaved delay are 0, 500, 1000, 2000, 4000, 8000, and 16000 microseconds. The default interleaved delay (the value assigned when a DSL profile is created) is 16000 microseconds for both upstream and downstream directions.

To set upstream and downstream interleaving delay for a specific DMT profile, follow these steps:

This command retrains the port if you change the parameter value. Setting a parameter to its previous value does not cause a retrain. If a port is training when you change this parameter, the port untrains and retrains to the new parameter value.

Example

This example sets the interleaving delay of the profile named "fast" to 2000 usec downstream and 4000 usec upstream, and displays the results:

CAP Interfaces

Table 4-5 shows the amount of delay (in milliseconds) that results from various combinations of baud rate, constellation, and cap interleaving-delay settings (short or long) on a 4-port flexi card configured for CAP. Interleaving delay is applied only in the downstream direction. Interleaving is not used on upstream traffic.

You can choose the interleaving-delay option none only when 136 k downstream baud rate is enabled. If you configure the interleaving-delay as none but the line card trains at a downstream bit rate that uses a baud rate that is other than 136 k, the actual interleaving-delay value is short.

The following table shows the relationship between the interleaving-delay value chosen and the state of the Reed-Solomon error correction function.

Note   If you set interleaving delay to none, the subscriber line might provide service at a higher bit rate than the one configured. This can happen because setting interleaving delay to none turns off Reed-Solomon error correction, and turning off error correction reduces the overhead on the line, leaving more bandwidth available to the subscriber.

To set the interleaving delay for a specific CAP profile, follow these steps:

To return the interleaved delay to its default (long) setting, follow these steps:

Examples

This example shows how to set the interleaving-delay value to none for the profile named "issis":

This example shows how to set the default interleaving delay value for the profile named "issis".

Setting the Number of Symbols per Reed-Solomon Codeword

This section describes how to set the number of symbols per Reed-Solomon codeword. This information applies to DMT interfaces only.

The allowable values for configured symbols per codeword are 1, 2, 4, 8, 16, or auto. If you select auto (automatic), the line card chooses the optimum symbols per codeword based upon the bit rate to which the line trains. The optimum value keeps the ratio of user data to error correction bytes roughly constant. The default symbols per codeword setting (the value assigned when a DSL profile is created) is auto for both upstream and downstream directions.

If the symbols per codeword is set explicitly (any value other than auto), the DSLAM attempts to match the configured symbols per codeword. However, depending upon the bit rate to which the port finally trains, some settings of symbols per codeword may not be achievable. When this occurs, the DSLAM chooses an actual symbols-per-codeword value that is closest (numerically) to the configured symbols per codeword. Table 4-6 lists the values of symbols per codeword that are allowable for various bit rate ranges.

When the training mode is set to quick, the modem DSP automatically chooses the codeword size. The one exception is that if check bytes is set to 0 and the training mode is quick, the codeword size is always 1.

To set the number of symbols per Reed-Solomon codeword, follow these steps:

If you set the codeword size to auto, the number of symbols per codeword depends upon the actual DMT bit rate. The default codeword size is auto.

This command retrains the port if you change the parameter value. Setting a parameter to its previous value does not cause a retrain. If a port is training when you change this parameter, the port untrains and retrains to the new parameter value.

Example

This example sets the number of symbols per Reed-Solomon codeword to 8 upstream and 16 downstream and displays the results:

Setting FEC Check (Redundancy) Bytes

This section describes how to set upstream and downstream interleaved FEC check (redundancy) bytes per Reed-Solomon (RS) codeword for a specific profile for DMT interfaces. The higher the check byte setting, the better the error correction, but the check bytes subtract from user bytes.

The configured number of FEC check bytes must be an even number in the range 0 to 16. The default (the value assigned when a DSL profile is created) is 16 check bytes for both the upstream and downstream directions.

If possible, the DSLAM sets the actual number of FEC check bytes to match the value configured in the profile. However, depending upon the bit rate to which the port finally trains, some settings of FEC check bytes may not be achievable. In this case, the DSLAM chooses an actual number of FEC check bytes that is closest (numerically) to the configured number of FEC check bytes. Table 4-7 lists the values of FEC check bytes that are achievable for all bit rates.

To set upstream and downstream FEC check (redundancy) bytes for a specific profile, follow these steps:

This command retrains the port if you change the parameter value. Setting a parameter to its previous value does not cause a retrain. If a port is training when you change this parameter, the port untrains and retrains to the new parameter value.

It is normally desirable to keep the ratio of check bytes to user bytes roughly constant regardless of the bit rate. This requires you to change both the check bytes and the codeword size parameters.

When the training mode is set to quick, the DSLAM automatically chooses the check bytes value. However, if check bytes is set to zero and the training mode is quick, the system always uses a check bytes value of 0.

Example

This example sets the FEC check bytes for the default profile to 6 upstream and 4 downstream and displays the results:

Enabling and Disabling Trellis Coding

To enable trellis coding, follow these steps:

To disable trellis coding, follow these steps:

This command retrains the port if you change the parameter value. Setting a parameter to its previous value does not cause a retrain. If a port is training when you change this parameter, the port untrains and retrains to the new parameter value.

The system can use trellis coding only if the profile enables it and the CPE supports trellis coding.

Example

This example turns off trellis encoding for the default profile and displays the results:

Setting the Overhead Framing Mode

To set the overhead framing mode of a DMT profile, follow these steps:

This command does not retrain the port when you change the parameter value.

If the actual framing mode used is the mode the ATU-C port requested, or if the ATU-R CPE does not support the ATU-C choice, then the highest mode the ATU-R does support is used.

Example

This example sets the overhead framing mode in the default profile to mode3 and displays the results:

Modifying the Operating Mode

To modify the operating mode of a DMT profile, follow these steps:

To set the operating mode of a DMT profile to the default mode, follow these steps:

An ADSL line uses one of these operating modes:

• auto—An ATU-C port that employs this operating mode automatically detects the capabilities of the ATU-R CPE and uses a startup sequence specified by either G.992.1, G.992.2, or T1.413-1998. Auto mode is the default for an ADSL line.
  
  
• g992-1—In this mode the line uses the G994.1 startup sequence. After startup, the line complies with G992.1 operation.
  
  
• g992-2—In this mode the line uses the G994.1 startup sequence. After startup, the line complies with G992.2 operation. (G992.2 is also known as G.lite.)
  
  
• t1-413—This mode forces the ATU-R CPE to use the T1.413-1998 startup sequence.
  
  

This command retrains the port if you change the parameter value. Setting a parameter to its previous value does not cause a retrain. If a port is training when you change this parameter, the port untrains and retrains to the new parameter value.

Example

This example sets the operating mode of the default profile to G992.1 and displays the results:

dsl profile default:

Link Traps Enabled: NO

Alarms Enabled: NO

ATM Payload Scrambling: Enabled

DMT profile parameters

Maximum Bitrates:

Interleave Path: downstream: 640 kb/s, upstream: 128 kb/s

Fast Path: downstream: 0 kb/s, upstream: 0 kb/s

Minimum Bitrates:

Interleave Path: downstream: 0 kb/s, upstream: 0 kb/s

Fast Path: downstream: 0 kb/s, upstream: 0 kb/s

Margin: downstream: 6 dB, upstream: 6 dB

Interleaving Delay: downstream: 16000 usecs, upstream: 16000 usecs

Check Bytes (FEC):

Interleave Path: downstream: 16, upstream: 16

Fast Path: downstream: 0, upstream: 0

R-S Codeword Size: downstream: auto, upstream: auto

Trellis Coding: Disabled

Overhead Framing: Mode 3

Operating Mode: G992-1

Training Mode: Quick

Minrate blocking: Disabled

SNR Monitoring: Disabled

Modifying the DMT Training Mode

To modify the training mode of a DMT profile, follow these steps:

To set the training mode of a DMT profile to its default value, follow these steps:

The above procedures specify the mode employed by the ATU-C port when it is training to an ATU-R CPE. There are two training modes:

• Standard—This mode uses the G.994.1 or T1.413-1998 initialization sequence depending on configuration. In standard training mode the ATU-C port trains with the modem once, and if the configured rates and settings are not obtainable, the line card reads the line quality and retrains, selecting the best available rates and settings. This mode allows more control over DMT parameters.
  
  
• Quick—This mode is the default. It uses the extended exchange sequence for T1.413-1998 initialization or the G.994.1 initialization, depending on configuration. In quick training mode the modem DSP automatically determines the best available rate based on the parameters provided. The DSP may be forced to change some of the configuration settings based on the line characteristics. This training mode is faster than the standard mode.
  
  

This command does not retrain the port when you change the parameter value.

Example

This example sets the training mode of the default profile to quick and displays the results:

Modifying the G.SHDSL Training Mode

To modify the training mode of a G.SHDSL profile, follow these steps:

Example

In the following example the training mode is configured as adaptive:

Setting the Power Spectral Density Mask for ATU-C CAP and ATU-C flexi CAP

This section describes how to set the ATU-C CAP and ATU-C flexi CAP power spectral density mask (PSDM) upstream and downstream values.

To set the ATU-C CAP and ATU-C flexi CAP PSDM upstream and downstream values, follow these steps:

Defaults

The default decibel values for PSDM rates are as follows:

• -40 dB downstream
  
  
• -38 dB upstream
  
  

Examples

In this example, the command sets the CAP PSDM value at -37 dB downstream and -41 dB upstream for the "issis" profile.

In this example, the command sets the CAP PSDM value to the default downstream and upstream settings of -40 dB and -38 dB for the "issis" profile.

Setting the Power Spectral Density Mask for SHTU-C

This section describes how to set the SHTU-C power spectral density mask (PSDM).

To set the SHTU-C PSDM, follow these steps:

Example

The following example shows you how to configure a symmetric mask type:

Setting SHTU-C Annex

You can set the SHTU-C annex type for each configuration profile. Use Annex A in North American network implementations. Annex B is appropriate for European SHDSL implementations. Use auto to allow the CO to detect the CPE side annex during training.

To set the annex type for a designated profile, follow these steps:

Example

The following example shows how to configure SHDSL Annex B:

Setting the ATU-C CAP CPE-Signature

You can set the customer premises equipment (CPE) signature for each configuration profile. The CPE signature indicates the CPE equipment supported feature set. To set the CAP CPE-signature for a designated profile, follow these steps:

Enabling and Disabling ATM Local Loopback

When you enable the loopback functionality, loopback cells are inserted on designated VPCs/VCCs. The NI-2 notifies you through the management information base (MIB) or Interim Local Management Interface (ILMI) if loopback cells do not return.

This section describes how to enable and disable ATM local loopback on a port.

To enable ATM local loopback on a port, follow these steps:

To disable ATM local loopback on a port, follow these steps:

This command retrains the port if you change the parameter. Setting a parameter to its previous value does not cause a retrain. If a port is training when you change this parameter, the port untrains and retrains to the new parameter.

Example

This command disables ATM local loopback for port 1 on slot 1 and displays the results:

Displaying DSL and ATM Status

To display DSL status for a line card and ATM status for a port, follow these steps:

Example

This example displays the DSL status for a 4xDMT line card and the ATM status for port 1 in slot 4:

Displaying Hardware Information

This section describes how to display information about the DSLAM hardware components.

To display a list of the cards in the chassis and the chassis type, and to indicate whether the power supply and fan interfaces are present, complete the following task:

To display the name of the card in the specified slot, complete the following task:

To display the manufacturing information for the card in the slot, including chassis type, chassis name, H/W revision, Serial #, Asset ID, Alias, and CLEI code, complete the following task:

To display the online insertion and removal (OIR) status of the line cards, complete the following task:

The show oir status command reports the status of line card slots in the DSLAM chassis. The reported status is one of the following:

• Loading—The line card in this slot is loading a new image, which typically takes about 2 minutes.
  
  
• Running—The line card in this slot is operating normally.
  
  
• Keepalive—The NI-2 is unable to communicate with the line card in this slot. The NI-2 keeps the line card in keepalive state for several seconds. If communication does not resume, the system assumes the card was removed.
  
  

When the NI-2 cannot communicate with a line card, the NI-2 provides no entry for the slot where the card is located. The show oir status command displays a history of attempts to communicate with the line card.

Examples

This example displays the physical card in the chassis and the chassis type and indicates if the power supply and fan interfaces are present:

This example displays information on the cards in slots 20 and 21:

This example displays the manufacturing information for the DSLAM, including information on the NI-2 card, backplane, I/O card, and power modules:

Posted: Mon Dec 9 15:04:02 PST 2002
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