|
|
To set the maximum and minimum allowed bit rates for the interleaved DMT profile parameters, use the dsl bitrate command.
dmt bitrate maximum interleaved downstream dmt-bitrate upstream dmt-bitrate
dmt-bitrate | The DMT bit rate is given as a multiple of 32 kbps. If you enter a nonmultiple of 32 kbps, the system rejects and aborts the command. See the allowed ranges and default values in "Usage Guidelines," below. |
See the default values in "Usage Guidelines," below.
Profile configuration
| Release | Modification |
|---|---|
12.0(5)DA | This command was introduced in a previous release. |
Only the alarm subsystem uses the minimum bitrate settings. Cisco IOS asserts an alarm if the line card trains at a rate below the configured minimum bitrate. However, no alarm is generated when alarms are disabled. See alarms, for more information on enabling and disabling alarms.
If alarms are enabled for the profile, setting the DMT bit rate to 0 disables the associated minimum DMT bit rate alarm.
Table 3-1 lists the allowable DMT bit rate ranges and default values.
| Configuration Parameter | Data Path | Downstream | Upstream | ||||
|---|---|---|---|---|---|---|---|
| Aggregate Range (kbps) | Path Range (kbps) | Path Default (kbps) | Aggregate Range (kbps) | Path Range (kbps) | Path Default (kbps) | ||
dmt bitrate max | Interleaved | 8032 to 32 | 8032 to 32 | 640 | 864 to 32 | 864 to 0 | 128 |
dmt bitrate min | Interleaved | 8032 to 32 | 8032 to 0 | 0 | 864 to 0 | 864 to 0 | 0 |
 |
Caution This command causes the port to retrain when you change the value of the bit rate 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.
In this example, the command sets the maximum interleaved bit rate of the default profile to 3200 kbps downstream and 640 kbps upstream:
DSLAM# configure terminal
DSLAM(config)# dsl-profile default
DSLAM(config-dsl-prof)# dmt bitrate maximum interleaved downstream 3200 upstream 640
Increasing the number of check bytes improves error correction, but slows performance. Set forward error correction (FEC) check bytes for a specific profile.
To set upstream and downstream FEC check (redundancy) bytes, use the command
dmt check-bytes interleaved downstream bytes upstream bytes
bytes | Enter the upstream and downstream FEC check bytes. The allowed values are 0, 2, 4, 6, 8, 10, 12, 14, and 16. |
Downstream: 16
Upstream: 16
Profile configuration
| Release | Modification |
|---|---|
12.0(5)DA | This command was introduced in a previous release. |
|
Caution This command causes the port to retrain when you change the check-bytes 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.
Conditions on the line, the configured bit rate, and the capabilities of the ATU-R CPE affect the achievable value for this parameter. As a result, the check-bytes value to which the line trains may be smaller than the value you configure. If you want to use more check bytes than the system is allowing you, use the dmt bitrate command to reduce the bit rate.
Use the command show dsl int atm slot#/port# to display the configured and actual check-bytes values for the connection.
In this example, the command sets the interleaved FEC check-bytes for the default profile to 12 downstream and 6 upstream:
DSLAM# configure terminal
DSLAM(config)# dsl-profile default
DSLAM(config-dsl-prof)# dmt check-bytes interleaved downstream 12 upstream 6
None
To set codeword size for upstream and downstream forward error correction (FEC) check (redundancy) bytes, use the dmt codeword-size command.
dmt codeword-size downstream {symbols | auto} upstream {symbols | auto}
symbols | The allowable values for codeword size (in symbols for each Reed-Solomon codeword) are 1, 2, 4, 8, and 16. |
auto | If you select a codeword size of auto, the system calculates the number of symbols for each codeword according to the achievable DMT bit rate. |
Downstream: auto
Upstream: auto
Profile configuration
| Release | Modification |
|---|---|
12.0(5)DA | This command was introduced in a previous release. |
|
Caution This 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 this parameter, the port untrains and retrains to the new parameter.
 |
Note Conditions on the line and the capabilities of the ATU-R CPE affect the achievable value for this parameter. As a result, the codeword-size value to which the line trains may not be the same as the value you configure. |
In this example, the command sets the codeword size for the default profile to 8 upstream and to auto downstream:
DSLAM# configure terminal
DSLAM(config)# dsl-profile default
DSLAM(config-dsl-prof)# dmt codeword-size downstream auto upstream 8
None
Trellis coding is a method of performing forward error correction. Improved error correction involves a decrease in speed. You enable or disable trellis coding for a specific profile.
To enable trellis coding for a profile, use the command dmt encoding trellis. To disable trellis coding for a profile, use the no form of the command.
dmt encoding trellisThis command has no keywords or arguments.
Disabled
Profile configuration
| Release | Modification |
|---|---|
12.0(5)DA | This command was introduced in a previous release. |
|
Caution This 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 this parameter, the port untrains and retrains to the new parameter.
In this example, the command turns off dmt encoding trellis for the default profile:
DSLAM# configure terminal
DSLAM(config)# dsl-profile default
DSLAM(config-dsl-prof)# no dmt encoding trellis
None
To set the interleaving delay parameter, use the command
dmt interleaving-delay downstream delay-in-usecs upstream delay-in-usecs
delay-in-usecs | Enter the interleaving delay in microsec. Allowable values are 0, 1000, 2000, 4000, 8000, and 16000 microsec. |
Downstream: 16000 microseconds
Upstream: 16000 microseconds
Profile configuration
| Release | Modification |
|---|---|
12.0(5)DA | This command was introduced in a previous release. |
|
Caution This command causes the port to retrain when you change the parameter. |
Setting this parameter to its current value does not cause a retrain. If a port is training when you change the value, the port untrains and retrains to the new value.
In this example, the command sets the interleaving delay of the default profile to 2000 microsec downstream and 4000 microsec upstream:
DSLAM# configure terminal
DSLAM(config)# dsl-profile default
DSLAM(config-dsl-prof)# dmt interleaving-delay downstream 2000 upstream 4000
None
To set upstream and downstream signal-to-noise ratio (SNR) margins for a DMT profile, use the dmt margin command.
dmt margin downstream dmt-margin upstream dmt-margin
dmt-margin | Enter the upstream and downstream SNR margins in decibels. The range is 0 to 15. |
Downstream: 6 dB
Upstream: 6 dB
Profile configuration
| Release | Modification |
|---|---|
12.0(5)DA | This command was introduced in a previous release. |
|
Caution This 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 this value, the port untrains and retrains to the new value.
In this example, the command sets the SNR DMT margins of the default profile to 12 dB downstream and 6 dB upstream:
DSLAM# configure terminal
DSLAM(config)# dsl-profile default
DSLAM(config-dsl-prof)# dmt margin downstream 12 upstream 6
None
To modify the operating mode of a line in the DSL profile, use the dmt operating-mode command. To set the operating mode to the default value, use the no form of the command.
dmt operating-mode {auto | g992-1 | g992-2 | t1-413}
auto | |
g992-1 | In this mode, the line uses the G994.1 startup sequence. After startup, the line complies to G992.1 operation. |
g992-2 | In this mode, the line uses the G994.1 startup sequence. After startup, the line complies to 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. |
auto
Profile configuration
| Release | Modification |
|---|---|
12.0(5)DA | This command was introduced in a previous release. |
12.1(1)DA | The g992-1, g992-2 , and t1-413 keywords were added; the splitterless keyword was removed. |
|
Caution This command causes the port to retrain when you change the parameter. |
If a port is training when you change the current value, the port untrains and retrains to the new value.
In this example, the command sets the operating mode of the default profile to g992-1:
DSLAM# configure terminal
DSLAM(config)# dsl-profile default
DSLAM(config-dsl-prof)# dmt operating-mode g992-1
To set the overhead framing mode, use the command
dmt overhead-framing {mode1 | mode2 | mode3}
mode1 | Full overhead framing with asynchronous bit-to-modem timing. |
mode2 | Full overhead framing with synchronous bit-to-modem timing. |
mode3 | Reduced overhead framing with separate fast and sync bytes in fast and interleaved latency buffers respectively. |
mode3
Profile configuration
| Release | Modification |
|---|---|
12.0(5)DA | This command was introduced in a previous release. |
|
Note Conditions on the line and the capabilities of the ATU-R CPE affect the achievable value for this parameter. As a result, the overhead framing value to which the line trains may not be the same as the value you configure. |
There are two types of ADSL framing:
1. Full overhead
2. Reduced overhead
There are also two versions of full overhead:
1. Asynchronous
2. Synchronous
You select the type of ASDL framing by choosing one of three modes:
|
Note Mode 3 is recommended for use on DMT interfaces adhering to the ANSI T1.413 Issue 2 standard. Mode 3 is required for Flexi card DMT interfaces. |
The number of overhead bytes per frame varies according to the overhead framing mode and the operating mode, as shown in Table 3-2.
| Framing Mode | Overhead Bytes | |||
|---|---|---|---|---|
| T1.413 and G992.1 | G992.2 | |||
| Downstream | Upstream | Downstream | Upstream | |
Mode 1 | 4 | 3 | 1 | 1 |
Mode 2 | 2 | 2 | 1 | 1 |
Mode 3 | 1 | 1 | 1 | 1 |
During the training sequence, the ATU-C indicates the highest framing structure number that it supports. It is assumed that, if the ATU-C indicates it supports framing structure k, it also supports all framing structures 0 to k-1.
If, during the training sequence, the ATU-R indicates a lower framing structure than that specified by the ATU-C, the ATU-C falls back to the framing structure number indicated by the ATU-R.
Management requirements drive the determination of overhead, full or reduced. Full overhead provides more bandwidth to the embedded operations channel (EOC), enabling higher polling rates. However, reduced overhead provides enough bandwidth to satisfy typical applications.
If an ADSL line supports an ATM link, you must choose a structure that disables synchronization control. If an ADSL line is supporting an STM link and the ADSL line interface has a clock tightly coupled to the stratum clock, synchronization control is not necessary.
The dmt overhead-framing command does not cause port retrain when you change the parameter.
In this example, the command sets the overhead framing mode in the profile named issis to mode 2:
DSLAM# configure terminal
DSLAM(config)# dsl-profile issis
DSLAM(config-dsl-prof)# dmt overhead-framing mode2
To modify the training mode in a DMT profile, use the dmt training-mode command in profile configuration mode. To set the training mode in a DMT profile to the default setting (quick), use the no form of the command.
dmt training-mode {standard | quick}
standard | Depending on the configuration, standard training uses either the T1.413-1998 or the G.994.1 initialization method. In standard training mode, the ATU-C line card trains 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. The line card software determines the best available rates. This mode allows more control over the DMT parameters. |
quick | This training mode uses either the extended exchange sequence for T1.413-1998 initialization or the G.994.1 initialization, depending on the configuration. In quick training mode the modem DSP automatically chooses the best available rate based on the parameters provided. The DSP might be forced to change some of the configuration settings based on line characteristics. This training mode is faster than standard training mode. |
|
Note This command applies to the 4DMT card only. A 4-port Flexi line card configured for DMT uses quick training all the time. |
quick
|
Note Cisco recommends that you use quick training mode on all interfaces. Standard training mode is not supported on 4-port Flexi line cards. |
Profile configuration
| Release | Modification |
|---|---|
12.0(5)DA | This command was introduced in a previous release. |
Quick training mode is recommended for all interfaces.
|
Caution This command causes the port to retrain when you change the training mode parameter. |
In this example, the command sets the training mode of the default profile to standard:
DSLAM# configure terminal
DSLAM(config)# dsl-profile default
DSLAM(config-dsl-prof)# dmt training-mode standard
To assign an identifier to a DSL circuit, use the dsl circuit command in interface configuration mode. To remove an identifier from a DSL circuit (that is, to leave the field blank), use the no form of the command.
dsl circuit circuit-id
circuit-id | The identifier you are assigning to the 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. |
There is no default value for this command.
Interface configuration
| Release | Modification |
|---|---|
12.0(5)DA | This command was introduced in a previous release. |
12.1(1)DA | DSL circuit identifier capability was added. |
None
In this example, the circuit ID 341 is assigned to slot 7, port 3.
DSLAM#configure terminal
DSLAM(config)# interface atm 7/3
DSLAM(config-if)# dsl circuit 341
To copy a DSL profile, use the dsl-copy-profile command.
dsl-copy-profile [force] source source-profile destination new-profile
[force] | Lets you overwrite the destination file, if it exists. |
source-profile | The profile whose information you want to copy to another profile |
new-profile | The destination profile |
There is no default value for this command.
Global configuration
| Release | Modification |
|---|---|
12.0(5)DA | This command was introduced in a previous release. |
12.1(1)DA | The capability to create a copy of an SDSL profile was added. |
If the destination profile indicated in this command does not exist, dsl-copy-profile creates it. The command then copies all configuration values in the source profile to the destination profile.
|
Note If you modify the source profile after issuing this command, the changes you make do not propagate to the destination profile. |
This command copies the default profile to a profile named my_default. If my_default does not exist, the command creates it.
DSLAM# configure terminal
DSLAM(config)# dsl-copy-profile force source default destination my_default
To create a DSL profile, or to select an existing profile for modification, use the dsl-profile command. To delete a DSL profile, use the no form of the command.
dsl-profile profile-name |
Note Cisco IOS includes two very similar commands, dsl-profile (in global configuration mode) and dsl profile (in interface configuration mode). Be sure you are using the correct command for your purpose. |
profile-name | The name of the profile you want to create, or an existing profile you want to delete or modify. |
By default, every port is attached to a special profile named "default."
|
Note You cannot delete the default profile or any profile that is attached to a port. |
Global configuration.
| Release | Modification |
|---|---|
12.0(5)DA | This command was introduced in a previous release. |
A profile is a named list of configured items. To configure a subscriber, you must attach a profile to that subscriber's port. You can change the configured items for a subscriber by changing that subscriber's profile.
You configure a port by using a configuration profile, rather than by direct configuration.
If you modify an existing profile, the change that you make takes effect on every ADSL port linked to that profile.
When you use the dsl-profile command, you might create a new profile with system-defined default values. The system automatically names this new profile "default."
If you change the default profile, the change does not propagate to the children of that default profile.
This configuration profile approach is in keeping with ADSL MIB standards.
This command implicitly creates a DSL profile named example, if it does not already exist. After you execute the steps shown here, you can modify the parameters for this profile:
DSLAM# configure terminal
DSLAM(config)# dsl-profile example
DSLAM(config-dsl-prof)#
In this example, the command modifies the default profile:
DSLAM# configure terminal
DSLAM(config)# dsl-profile default
DSLAM(config-dsl-prof)#
To attacha port to a profile, use the dsl profile command in interface configuration mode. To detach the port from its profile and attach the default profile, use the no form of the command.
dsl profile [profile-name] |
Note Cisco IOS includes two very similar commands, dsl-profile (in global configuration mode) and dsl profile (in interface configuration mode). Be sure you are using the correct command for your purpose. |
profile-name | The profile you want to attach to the selected port. |
There is no default value for this command.
Interface configuration
| Release | Modification |
|---|---|
12.0(5)DA | This command was introduced in a previous release. |
A profile is a named list of configured items. To configure a subscriber, you must attach a profile to that subscriber's port. You can change the configured items for a subscriber by changing that subscriber's profile.
Except for a few dynamic operational modes, port configuration takes place through a configuration profile, rather than by direct configuration.
If you modify an existing profile, the change that you make takes effect on every ADSL port linked to that profile.
This configuration profile approach is in keeping with ADSL 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, there can be one profile for many ports, but one port cannot have more than one profile. 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.
All ports have attached profiles. If you do not assign a profile to a port, the system, by default, assigns the profile named "default."
In this example, the command attaches the profile test1 to slot 20, port 1:
DSLAM# configure terminal
DSLAM(config)# interface atm 20/1
DSLAM(config-if)# dsl profile test1
To assign a name to a DSL port, use the dsl subscriber command in interface configuration mode. To remove a name from a port (that is, to leave the field blank), use the no form of the command.
dsl subscriber name
name | The string you are defining as the name of the port. The string may 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. |
There is no default value for this command.
Interface configuration
| Release | Modification |
|---|---|
12.0(5)DA | This command was introduced in a previous release. |
You can use the port name to identify the subscriber the port serves.
In this example, the name paul is assigned to slot 7, port 3.
DSLAM# configure terminal
DSLAM(config)# interface atm 7/3
DSLAM(config-if)# dsl subscriber paul
To run the line card port self-test, use the command
dsl test atm slot#/port# self
slot#/port# | The slot and port numbers for which you want to run the line card chipset self-test. The slot range is 1 to 38. The port range is 1 to 8. (These are maximum ranges; your card might have fewer than 8 ports and your chassis might have fewer than 38 slots.) |
There is no default value for this command.
Exec
| Release | Modification |
|---|---|
12.0(5)DA | This command was introduced in a previous release. |
This command runs a digital bit error-rate loopback test on the specified port. The run time for the self-test ranges from 3 seconds for the ATUC-1-4DMT card to 1 minute for the 4-port Flexi card.
To view the result of the self-test, use the command show dsl interface atm slot#/port#.
The output display for this command includes the result of the last self-test, such as
Last Self-Test Result: NONE
The possible self-test results are PASSED, FAILED, RUNNING, and NONE.
The NONE result means that a chipset self-test has not run since the port became operational.
RUNNING means the test is in progress.
|
Caution The line card port self-test disrupts port operation. If a port has been trained or is training when this test begins, the port becomes untrained, the test executes, and the port retrains. |
In this example, the command runs the self-test for port 1 in slot 20:
DSLAM# dsl test atm 20/1 self
Posted: Wed Jul 24 12:02:25 PDT 2002
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