# Link Configuration Mode Commands

The Link configuration mode defines the MTP3 link parameters for a specific link in a linkset of an SS7 routing domain instance.
In this mode, the prompt will be similar to:

    [local]hostname(config-ss7-rd-linkset-<#>-link-<#>)#

IMPORTANT:

The commands or keywords/variables that are available are dependent on platform type, product version, and installed license(s).
arbitration

This command configures link arbitration.
Platform:

ASR 5000
Product:

SGSN
Privilege:

Security Administrator, Administrator
Syntax

    arbitration { active | passive }no arbitration

no

Removes the arbitration configuration for the link.
active

The SSCOP initiates the transmission of PDUs.
passive

The SSCOP waits to receive PDUs.
Usage:

Sets the configuration to initiate transmission of PDUs.

Example

Example

    arbitration active

end

Exits the current configuration mode and returns to the Exec mode.
Product:

All
Privilege:

Security Administrator, Administrator
Syntax

    end

Usage:

Use this command to return to the Exec mode.
exit

Exits the current mode and returns to the parent configuration mode.
Product:

All
Privilege:

Security Administrator, Administrator
Syntax

    exit

Usage:

Use this command to return to the parent configuration mode.
mtp2-aerm-emergency-threshold

Configure the alignment error rate monitor (AERM) emergency threshold value. This command is only available for a lowspeed-narrowband link-type.
Platform:

ASR 5000
Product:

SGSN
Privilege:

Security Administrator, Administrator
Syntax

    mtp2-aerm-emergency-threshold valuedefault mtp2-aerm-emergency-threshold

default

Resets the parameter to the default value of 1.
value

value : Enter an integer from 1 to 50. Default: 1.
Usage:

This command sets the emergency threshold for the MTP2 alignment error rate monitor.

Example

Example
Set the emergency AERM threshold to 17:

    mtp2-aerm-emergency-threshold 17

mtp2-aerm-normal-threshold

Configure the alignment error rate monitor (AERM) normal threshold value. This command is only available for a lowspeed-narrowband link-type.
Platform:

ASR 5000
Product:

SGSN
Privilege:

Security Administrator, Administrator
Syntax

    mtp2-aerm-normal-threshold value

    default mtp2-aerm-normal-threshold

default

Resets the parameter to the default value of 4.
value

value : Enter an integer from 4 to 100. Default: 4.
Usage:

This command sets the normal threshold for the MTP2 alignment error rate monitor.

Example

Example
Set the normal AERM threshold to 55:

    mtp2-aerm-normal-threshold 55

mtp2-eim-decrement

Configure the errored interval monitor (EIM) emergency decrement value. This command is only available for a highspeed-narrowband link-type.
Platform:

ASR 5000
Product:

SGSN
Privilege:

Security Administrator, Administrator
Syntax

    mtp2-eim-decrement value

    default mtp2-eim-decrement

default

Resets the parameter to the default value of 11.
value

value : Enter an integer from 1 to 63. Default: 11.
Usage:

This command sets the emergency decrement value for the EIM.

Example

Example
Reset the EIM emergency decrement to 1:

    default mtp2-eim-decrement

mtp2-eim-increment

Configure the errored interval monitor (EIM) emergency increment value. This command is only available for a highspeed-narrowband link-type.
Platform:

ASR 5000
Product:

SGSN
Privilege:

Security Administrator, Administrator
Syntax

    mtp2-eim-increment value

    default mtp2-eim-increment

default

Resets the parameter to the default value of 198.
value

value : Enter an integer from 1 to 1023. Default: 198.
Usage:

This command sets the emergency increment value for the EIM.

Example

Example
Set the EIM emergency increment to 2:

     mtp2-eim-increment
     2

mtp2-eim-threshold

Configure the errored interval monitor (EIM) emergency threshold value. This command is only available for a highspeed-narrowband link-type.
Platform:

ASR 5000
Product:

SGSN
Privilege:

Security Administrator, Administrator
Syntax

    mtp2-eim-threshold value

    default mtp2-eim-threshold

default

Resets the parameter to the default value of 794.
value

value : Enter an integer from 1 to 65535. Default: 794.
Usage:

This command sets the emergency threshold value for the EIM.

Example

Example
Set the EIM emergency threshold to 154:

     mtp2-eim-threshold
     154

mtp2-error-correction

Configure the error correction method to be used. This command is only available for lowspeed or highspeed narrowband link-types.
Platform:

ASR 5000
Product:

SGSN
Privilege:

Security Administrator, Administrator
Syntax

    mtp2-error-correction { basic | preventive-cyclic-retransmission }

    default mtp2-error-correction

default

Resets the parameter to the default value.
basic

Basic error correction (BEC) is a positive / negative acknowledgement method that uses backwards retransmission. This method is best for links with less than 30 ms one-way propagation delays.
preventtive-cyclic-retransmission

PCR is recommended for links with 125 ms, or higher, propagation delays.
Usage:

Set the method of MTP2 layer error correct to be used on the link.

Example

Example
Set error correction for a link with 15 ms propagaion delay::

     mtp2-error-correction
    basic

mtp2-lssu-len

This command sets the length of the link status signal unit (LSSU) which carries link status information used to manage link alignment and indicate the status of the signaling points to each other. This command is only available for lowspeed or highspeed narrowband link-types.
Platform:

ASR 5000
Product:

SGSN
Privilege:

Security Administrator, Administrator
Syntax

    mtp2-lssu-len #_octetsdefault mtp2-lssu-len

default

Using this keyword with the command resets the length to the default of 1 octet.
#_octets

Sets the number of octets for the length of the LSSU.

#_octets: Must be either 1 or 2.
Usage:

Use this command to define the maximum amount of link status information that is to be shared between signaling points.
Example:
You can use the following command to set the LSSU length to 2 octets - the maximum length:

    mtp2-lssu-len 2

mtp2-max-outstand-frames

This command sets the maximum number of outstanding packets to be sent by the link manager (linkmgr) - applicable for both high speed (HSL) and low speed (LSL) narrowband links.
Platform:

ASR 5000
Product:

SGSN
Privilege:

Security Administrator, Administrator
Syntax

    mtp2-max-outstand-frames #_bytesdefault mtp2-max-outstand-frames

default

Using this keyword with the command resets number of packets to the default of 7 bytes.
#_bytes

Sets the maximum number of packets sent by the linkmgr that can be allowed to be outsanding.

#_bytes: Must be an integer from 5 to 10.
Usage:

The linkmgr (MTP2) sends data at a higher rate, than the narrowband (NB) E1 link speed, when in congestion and performing retransmission. This can lead to more congestion leading to more time taken for the link to come out of congestion. If using a value of 10 during congestion, then linkmgr pumps data at a rate higher than 2.5 mbps. To avoid this problem, a lower value is usually considered optimal. This configuration holds good for both HSL and LSL.
Example:
Use the following command to reset the default number of outstanding packets sent by the LinkMgr:

    default mtp2-max-outstand-frames

Set the maximum number of oustanding packets the linkmgr can send to 6:

    mtp2-max-outstand-frames 6

mtp2-suerm-threshold

Configure the signal unit error rate monitor (SUERM) threshold. This command is only available for lowspeed-narrowband link-types.
Platform:

ASR 5000
Product:

SGSN
Privilege:

Security Administrator, Administrator
Syntax

    mtp2-suerm-threshold value

    default mtp2-suerm-threshold

default

Resets the parameter to the default value.
value

Defines the threshold for number of bad frames

value: Enter an integer from 64 to 1023. Default is 64.
Usage:

Sets the threshold for link monitoring of bad frames.

Example

Example
Set a new link monitoring bad frames (SEURM) threshold of 256:

     mtp2-suerm-threshold 256

mtp3-discard-priority

Configure MTP3 message discard priority.
Platform:

ASR 5000
Product:

SGSN
Privilege:

Security Administrator, Administrator
Syntax

    mtp3-discard-priority prioritydefault mtp3-discard-priority

default

Resets the priority to the default value.
priority

priority: must be an integer between 0 and 3.

Default is 0.
Usage:

Use this command to manage MTP3 messaging.

Example

Example

    mtp3-discard-priority 2

mtp3-max-slt-try

Configure maximum number of times to retry SLT (signaling link test).
Platform:

ASR 5000
Product:

SGSN
Privilege:

Security Administrator, Administrator
Syntax

    mtp3-max-slt-try retriesdefault mtp3-max-slt-try

default

Resets the number of retries to the default value.
retries

retries: must be an integer between 1 to 65535.

Default is 10.
Usage:

Use this command to troubleshoot MTP3 link mismatch.

Example

Example

    mtp3-max-slt-try 35

mtp3-msg-priority

Configures the priority for sending MTP3 management messages.
Platform:

ASR 5000
Product:

SGSN
Privilege:

Security Administrator, Administrator
Syntax

    mtp3-msg-priority prioritydefault mtp3-msg-priority

default

Resets the number of priority to the default value.
priority

priority: must be an integer from 0 to 3.

Default: 0
Usage:

Use this command to set the priority for sending MTP3 management messages.

Example

Example
Use the following to set the message priority to 3:

    mtp3-msg-priority 3

mtp3-msg-size

Configures the size of messages from layer 3 to layer 2.
Platform:

ASR 5000
Product:

SGSN
Privilege:

Security Administrator, Administrator
Syntax

    mtp3-msg-size sizedefault mtp3-msg-size

default

Resets the the size to the default value which is 4096 (for q.2140) or 272 (for MTP2)
size

size: must be an integer from 1 to 272 for high-speed or low-speed narrowband SS7 links.

size: must be an integer from 1 to 4096 for ATM broadband links.
Usage:

Use this command to set the maximum message size, in bytes.

Example

Example
Use this command to set the MTP3 message size to 4096 bytes:

    mtp3-msg-size 4096

mtp3-p1-qlen

Configure the size for the MTP3 p1 queue length.
Platform:

ASR 5000
Product:

SGSN
Privilege:

Security Administrator, Administrator
Syntax

    mtp3-p1-qlen sizedefault mtp3-p1-qlen

default

Resets the number of size of the priority 1 queue to the default value.
size

size: integer from 1 to 65535. Size should be less than MTP3 p2 qlen and p3 qlen.

Default: 1024
Usage:

Use this command to configure the queue length threshold for raising the congestion priority to level 1.

Example

Example
Use this command to set the queue length priority to 128:

    mtp3-p1-qlen 128

mtp3-p2-qlen

Configure the size of the priority 2 queue.
Platform:

ASR 5000
Product:

SGSN
Privilege:

Security Administrator, Administrator
Syntax

    mtp3-p2-qlen sizedefault mtp3-p2-qlen

default

Resets the number of size of the priority 2 queue to the default value.
size

size: integer from 1 to 65535. Size should be less than MTP3 p3 qlen and greater than p1 qlen.

Default: 1024
Usage:

Use this command to configure the queue length threshold for raising the congestion priority to level 2.

Example

Example
Use this command to set the queue length threshold to 256:

    mtp3-p2-qlen 256

mtp3-p3-qlen

Configure the size of the priority 3 queue.
Platform:

ASR 5000
Product:

SGSN
Privilege:

Security Administrator, Administrator
Syntax

    mtp3-p3-qlen sizedefault mtp3-p3-qlen

default

Resets the number of size of the priority 3 queue to the default value.
size

size: integer from 1 to 65535. Size should be greater than MTP3 p1 qlen and p2 qlen .

Default: 1024
Usage:

Use this command to configure the queue length threshold for raising the congestion priority to level 3.

Example

Example

    mtp3-p3-qlen 1024

mtp3-test-pattern

Configures the character string for the test message.
Platform:

ASR 5000
Product:

SGSN
Privilege:

Security Administrator, Administrator
Syntax

    mtp3-test-pattern patterndefault mtp3-test-pattern

default

Resets the pattern to the default value.
pattern

pattern: 1 to 15 alphanumeric characters.

Default: SGSN-ORIGINATED
Usage:

Use this command to define a test pattern string for the signalling link test match (SLTM).
Example:

    mtp3-test-pattern TEST1-HomeOffice

priority

Configures the MTP3 Link Priority.
Platform:

ASR 5000
Product:

SGSN
Privilege:

Security Administrator, Administrator
Syntax

    priority pri_valueno priority

no

Removes the priority configuration.
pri_value

pri_value: 0 represents highest priority and 15 represents the lowest priority.
Usage:

Use this command to configure the link priority within the MTP3 link set.

Example

Example

    priority 2

signaling-link-code

Configures the signaling link code (SLC).
Platform:

ASR 5000
Product:

SGSN
Privilege:

Security Administrator, Administrator
Syntax

    signaling-link-code codeno signaling-link-code

no

Removes the SLC configuration.
code

code: integer from 0 to 15.
Usage:

Use this command to uniquely identify the signaling link to be used for MTP3 management messages.

Example

Example

    signaling-link-code 4

sscf-nni-n1

Configures the SSCF NNI N1. This command is only available for ATM-broadband link-types.
Platform:

ASR 5000
Product:

SGSN
Privilege:

Security Administrator, Administrator
Syntax

    sscf-nni-n1 valueno sscf-nni-n1

default

Removes the sscf-nni-n1 configuration.
value

value: integer from 1 to 65535.

Default: 1000
Usage:

Use this command to identify the network-to-node interface (NNI) between the MTP3 and SSCOP layers.

Example

Example

    sscf-nni-n1 4064

sscop-max-cc

Configure the maximum value for the SSCOP connection control (CC) state variable. his command is only available for ATM-broadband link-types.
Platform:

ASR 5000
Product:

SGSN
Privilege:

Security Administrator, Administrator
Syntax

    sscop-max-cc valueno sscop-max-cc

default

Removes the sscop-max-cc configuration.
value

value: integer from 1 to 65535.

Default: 4
Usage:

Use this command as part of the configuration responsible for managing the SSCOP connection. This command sets the number of times retries.

Example

Example

    sscop-max-cc 256

sscop-max-pd

Configures the maximum acceptable value for the SSCOP state variable VT(PD). his command is only available for ATM-broadband link-types.
Platform:

ASR 5000
Product:

SGSN
Privilege:

Security Administrator, Administrator
Syntax

    sscop-max-pd valueno sscop-max-pd

default

Removes the sscop-max-pd configuration.
value

value: integer from 1 to 65535.

Default: 500
Usage:

Use this command to define the maximum number of data PDUs transmitted between POLL PDUs.

Example

Example

    sscop-max-pd 2500

sscop-max-stat

Configures the maximum number of elements included in a status PDU. his command is only available for ATM-broadband link-types.
Platform:

ASR 5000
Product:

SGSN
Privilege:

Security Administrator, Administrator
Syntax

    sscop-max-stat valueno sscop-max-stat

default

Removes the sscop-max-stat configuration.
value

value: integer from 3 to 65535. This parameter should be an odd integer greater than or equal to 3.

Defaultz; 67
Usage:

Received in response to a POLL PDU, the STAT PDU includes information about the number of SD PDUs that have been received.

Example

Example

    sscop-max-stat 56000

timeout

This command enables configuration of an array of signaling and flow control timers - for MTP, SSCF, and SSCOP.
Platform:

ASR 5000
Product:

SGSN
Privilege:

Security Administrator, Administrator
Syntax

    [ no ] timeout timer timer_value

no

Adding no to the timeout command removes the timer configuration.
timer timer_value

Select the timer and enter a value from the range.

For timers having different ranges for highspeed and lowspeed links or for different variants, the appropriate ranges will be displayed based on the link-type configured.

IMPORTANT:

Currently, the China variant uses ITU values.

Timer | Link Type & Variant | Range of Times Granularity = 100ms | Default Time
--- | --- | --- | ---
mtp2-tmr-t1 Alignment ready timer | Highspeed; ITU | 160..3500 (16 - 350 seconds) | 3000 (300 seconds)
| Lowspeed; ITU | 120 - 500 (12 - 50 seconds) | 400 (40 seconds)
| Highspeed; ANSI | 160 - 3500 (16 to 350 seconds) | 1700 (170 seconds)
| Lowspeed; ANSI | 120 - 500 (12 - 50 seconds) | 130 (13 seconds)
mtp2-tmr-t2 Not aligned timer | Highspeed; ITU | 50 - 1500 (5 - 150 seconds) | 50 (5 seconds)
| Lowspeed; ITU | 50 - 150 (5 - 15 seconds) | 50 (5 seconds)
| Highspeed; ANSI | 50 - 1500 (5 - 150 seconds) | 230 (23 seconds)
| Lowspeed; ANSI | 50 - 150 (5 - 15 seconds) | 115 (11.5 seconds)
mtp2-tmr-t3 Aligned timer | Highspeed/Lowspeed; ITU | 10 - 140 (1 - 14 seconds) | 15 (1.5 seconds)
| Highspeed/Lowspeed; ANSI | 10 - 140 (1 - 14 seconds) | 115 (11.5 seconds)
mtp2-tmr-t4e Emergency proving period timer | Highspeed; ITU | 4 - 60 (400 milliseconds - 6 seconds) | 5 (500 milliseconds)
| Lowspeed; ITU | 4 - 6 (400 - 600 milliseconds) | 5 (500 milliseconds)
| Highspeed; ANSI | 4 - 60 (400 milliseconds - 6 seconds) | 50 (5 seconds)
| Lowspeed; ANSI | 4 - 6 (400 - 600 milliseconds) | 6 (600 milliseconds)
mtp2-tmr-t4n Normal proving period timer Once set this timer can be reset but it can not be disabled. | Highspeed; ITU | 30 - 700 (3 to 70 seconds) | 3 (30 seconds)
| Lowspeed; ITU | 20 - 95 (2 - 9.5 seconds) | 82 (8.2 seconds)
| Highspeed; ANSI | 30 - 700 (3 to 70 seconds) | 3 (30 seconds)
| Lowspeed; ANSI | 20 - 95 (2 - 9.5 seconds) | 23 (2.3 seconds)
mtp2-tmr-t5 Sending status indication busy (SIB) timer | Highspeed/Lowspeed ITU/ANSI | 1 - 2 (100 - 200 milliseconds) | 1 (100 milliseconds)
mtp2-tmr-t6 Remote congestion timer | Highspeed/Lowspeed ITU/ANSI | 10 - 60 (1 to 6 seconds) | 30 (3 seconds)
mtp2-tmr-t7 Excessive delay of acknowledgement timer | Highspeed/Lowspeed ITU/ANSI | 5 - 20 (500 milliseconds - 2 seconds) | 10 (1 second)
mtp2-tmr-t8 Interval timer for error interval monitor timer | Highspeed ITU/ANSI | 1 - 2 (100 - 200 milliseconds) | 1 (100 milliseconds)
mtp3-tmr-t1 Delay to avoid mis-sequencing on changeover timer | Highspeed/Lowspeed ITU/ANSI | 5 - 12 (500 - 1200 milliseconds) | 5 (500 milliseconds
mtp3-tmr-t12 Waiting for uninhibit acknowledgement timer | Highspeed/Lowspeed ITU/ANSI | 8 - 15 (800 - 1500 milliseconds | 8 (800 milliseconds
mtp3-tmr-t13 Waiting for force uninhibit timer | Highspeed/Lowspeed ITU/ANSI | 8 - 15 (800 - 1500 milliseconds | 8 (800 milliseconds
mtp3-tmr-t14 Waiting for inhibition acknowledgement timer | Highspeed/Lowspeed ITU/ANSI | 20 - 30 (2000 - 3000 milliseconds | 20 (2000 milliseconds
mtp3-tmr-t17 Delay to avoid oscillation of initial alignment failure and link restart | Highspeed/Lowspeed ITU/ANSI | 8 - 15 (800 - 1500 milliseconds | 8 (800 milliseconds
mtp3-tmr-t2 Waiting for changeover acknowledgement | Highspeed/Lowspeed ITU/ANSI | 7 - 20 (700 - 2000 milliseconds | 7 (700 milliseconds
mtp3-tmr-t22 Local inhibit test timer | Highspeed/Lowspeed ITU/ANSI | 1800 - 3000 (180 - 300 seconds | 1800 (180 seconds)
mtp3-tmr-t23 Remote inhibit test timer | Highspeed/Lowspeed ITU/ANSI | 1800 - 3000 (180 - 300 seconds | 1800 (180 seconds)
mtp3-tmr-t24 Stabilising timer after removal of local processor outage, used in LPO latching to RPO (national option) | Highspeed/Lowspeed ITU/ANSI | 5 - 15 (500 - 1500 milliseconds) | 5 (500 milliseconds)
mtp3-tmr-t3 Time controlled diversion-delay to avoid mis-sequencing on changeback | Highspeed/Lowspeed ITU/ANSI | 5 - 12 (500 - 1200 milliseconds) | 5 (500 milliseconds)
mtp3-tmr-t31 BSN requested timer | Highspeed/Lowspeed ITU/ANSI | 50 - 100 (5 to 10 seconds) | 50 (5 seconds)
mtp3-tmr-t32 SLT timer | Highspeed/Lowspeed ITU/ANSI | 40 - 120 (4 - 12 seconds) | 100 (10 seconds)
mtp3-tmr-t33 Connecting timer | Highspeed/Lowspeed ITU/ANSI | 50 - 100 (5 to 10 seconds) | 50 (5 seconds)
mtp3-tmr-t34 Periodic signalling link test timer | Highspeed/Lowspeed ITU/ANSI | 300 - 900 (30 to 90 seconds) | 600 (60 seconds)
mtp3-tmr-t4 Waiting for changeback acknowledgement (first attempt) | Highspeed/Lowspeed ITU/ANSI | 5 - 12 (500 to 1200 milliseconds) | 5 (500 milliseconds)
mtp3-tmr-t5 Waiting for changeback acknowledgement (second attempt) | Highspeed/Lowspeed ITU/ANSI | 5 - 12 (500 to 1200 milliseconds) | 5 (500 milliseconds)
mtp3-tmr-t7 Waiting for signalling data link connection acknowledgement | Highspeed/Lowspeed ITU/ANSI | 10 - 20 (1000 - 2000 milliseconds) | 10 (1000 milliseconds)

Timer | Link type & Variant | Range of Times | Default Time
--- | --- | --- | ---
sscf-nni-tmr-t1 | ATM Broadband ITU/ANSI | 1 - 65535 (10 - 655350 milliseconds) Granularity = 10 ms | 500 (5 seconds)
sscf-nni-tmr-t2 | ATM Broadband ITU/ANSI | 1 - 65535 (10 - 655350 milliseconds) Granularity = 10 ms | 3000 (30 seconds)
sscf-nni-tmr-t3 | ATM Broadband ITU/ANSI | 1 - 65535 (10 - 655350 milliseconds) Granularity = 10 ms | 1 (10 milliseconds)
sscop-tmr-cc SSCOP CC timer | ATM Broadband ITU/ANSI | 1 - 65535 (100 - 6553500 milliseconds) Granularity = 100 ms | 2 (200 milliseconds)
sscop-tmr-idle SSCOP idle timer (UNI 3.1 only) | ATM Broadband ITU/ANSI | 1 - 65535 (100 - 6553500 milliseconds) Granularity = 100 ms | 1 (100 milliseconds)
sscop-tmr-keep-alive SSCOP keep alive timer For stability purposes, tmrKeepAlive >/= tmrPoll and tmrKeepAlive < tmrNoResponse. | ATM Broadband ITU/ANSI | 1 - 65535 (100 - 6553500 milliseconds) Granularity = 100 ms | 1 (100 milliseconds)
sscop-tmr-no-rsp SSCOP no response timer For stability purposes, tmrNoResponse > tmrKeepAlive. | ATM Broadband ITU/ANSI | 1 - 65535 (100 - 6553500 milliseconds) Granularity = 100 ms | 15 (1.5 seconds)
sscop-tmr-poll SSCOP poll timer For stability purposes, tmrPoll <= tmrKeepAlive. | ATM Broadband ITU/ANSI | 1 - 65535 (100 - 6553500 milliseconds) Granularity = 100 ms | 1 (100 milliseconds)

Usage:

For a single link and specified link-type (highspeed or lowspeed), this command sets the timer values listed above. The SS7 variant is determined when the SS7 routing domain is first defined from the Global Configuration mode.

Repeat the timeout command (one timer and value per entry) as needed to configure all required timers.

IMPORTANT:

Currently, the China variant uses the same timers, values, and defaults as the ITU variant.

Example

Example

    timeout timer timer_value