# SGSN PSP Configuration Mode Commands

The Peer-Server Process (PSP) configuration mode provides the commands to create, configure, bind, and manage a specific PSP instance included in an SS7 routing domain configuration.
In this mode, where information in italics is customer-defined, the command prompt should appear similar to:

    [local]hostname(config-ss7-rd-1-ps-1-psp-1)#

IMPORTANT:

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

Defines an association between the PSP instance and an application server process (ASP) instance.
Platform:

ASR 5000
Product:

SGSN
Privilege:

Security Administrator, Administrator
Syntax

    associate { asp
    instance  asp_num }no associate [ asp ]

no

Removes the association, between the PSP and the ASP, from the routing domain configuration.

IMPORTANT:

Using the no associate command will most likely result in the termination of all current subscriber sessions active through the peer-server.
asp instance asp_num

Identifies a specific ASP configuration. Up to four ASP instances can be configured for a single SS7 routing domain.

asp_num is a digit from 1 to 4.
Usage:

Use this command to create an association between a specific peer-server process (PSP) and a specific application server process (ASP) instance or a specific differentiated services code point (DSCP marking template).

Before using the associate command, the values for the psp-mode and end-point commands must be configured.

Before using the associate command, the M3UA end-point of the ASP must be configured. Use the commands defined in the ASP Configuration Mode chapter of the Command Line Interface Reference.

Example

Example
Associate this PSP instance with ASP configuration instance 2 :

    associate asp instance
    2

Use the following command to terminate all associations with this PSP instance:

    no associate

end

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

All
Privilege:

Security Administrator, Administrator
Syntax

    end

Usage:

Change the mode back to the Exec mode.
end-point

This command defines or deletes the IP address to be associated with the local SCTP end-point for the application server process (ASP).
Platform:

ASR 5000
Product:

SGSN
Privilege:

Security Administrator, Administrator
Syntax

    end-point { address ip_address | port port_number }no end-point [ address ip_address ]

no

Removes the ASP end-point association configuration from the PSP configuration.

IMPORTANT:

This command can not be used as long as the PSP and the ASP are associated. Use the no associate command when entering any form of this command, including no end-point. When the change is made, re-enter the ASP association with the association command.
port port_number

Configures the M3UA’s SCTP port number for the end-point.

port_number: Must be an integer from 1 to 65535.

Default: 2905.
Usage:

Use this command to manage the ASP end-point. At least one address needs to be configured for the ASP before the end-point can be associated with the PSP.
Example:
Set the ASP end-point to IP address 192.168.1.1 with the following command:

    end-point address
    192.168.1.1

exchange-mode

Configures the exchange-mode for the PSP communication.
Platform:

ASR 5000
Product:

SGSN
Privilege:

Security Administrator, Administrator
Syntax

    exchange-mode [ double-ended | single-ended ]

Usage:

IMPORTANT:

Before using this command to set a value or reset the default, you must disassociate the PSP instance with the no associate command. When you have modified your configuratioin with this command, then use the associate command to setup a new ASP association.

Use this command to toggle the exchange modes for the PSP to match the exchange mode supported by the ASP. The exchange mode specifies what type of ASP messages exchange is used in an IPSP communication.

The exchange-mode must be configured for ‘single-ended’ if the psp-mode has been configured for ‘client’.

Example

Example
Change the exchange mode from the standard double-ended to single-ended:

    exchange-mode single-ended

exit

Exits the current configuration mode and moves to the previous configuration mode.
Product:

All
Privilege:

Security Administrator, Administrator
Syntax

    exit

Usage:

Return to the Peer-Service configuration mode.
psp-mode

Configures either client-mode or server-mode as the PSP’s operational mode.
Platform:

ASR 5000
Product:

SGSN
Privilege:

Security Administrator, Administrator
Syntax

    psp-mode { client | server }

client

The PSP operates as a client.
server

The PSP operates as a server.
Usage:

IMPORTANT:

Before using this command to change the configuration, you must disassociate the PSP instance with the no associate command. When you have modified your configuratioin with this command, then use the associate command to setup a new ASP association.

Instruct the peer-server process to operate in either client or server mode.

Example

Example
Configure the PSP to operate in server mode:

    psp-mode server

routing-context

Configures the behavior of the routing context in M3UA messages.

IMPORTANT:

This keyword function is only available in releases 8.1 and higher.
Platform:

ASR 5000
Product:

SGSN
Privilege:

Security Administrator, Administrator
Syntax

    routing-context { discard-inbound | process-inbound { insert-outbound | suppress-outbound }default routing-context

default

Include this keyword with the command, to reset the configuration to the system default for routing-context which is a combination of process-inbound and insert-outbound.
discard-inbound

Sets the routing context received in M3UA messages to be discarded.
process-inbound

Sets the routing context received in M3UA messages to be processed.
insert-outbound

Sets the routing context so that it is added in the M3UA messages.
suppress-outbound

Sets the routing context so that it is suppressed in the M3UA messages.
Usage:

IMPORTANT:

Before using this command to change the configuration or reset the default, you must disassociate the PSP instance with the no associate command. When you have modified your configuratioin with this command, then use the associate command to setup a new ASP association.

In PSP (singled-ended) configuration mode, the settings for both the local routing context (the SGSN's routing context) and the peer routing context (the RNC's routing context) should be the same. If the routing contexts created at the SGSN and on the peer are different then this can cause the M3UA link to fail.

Routing context is an optional parameter when an M3UA association has only one associated peer-server.

Example

Example
If the peer does not support routing context, then disable the routing context feature:

    routing-context discard-inbound
    suppress-outbound

sctp-alpha

This stream control transmission protocol (SCTP) retransmission time out (RTO) parameter defines the RTO-Alpha value.
Platform:

ASR 5000
Product:

SGSN
Privilege:

Security Administrator, Administrator
Syntax

    sctp-alpha  value

    default sctp-alpha

value

Defines a percentage (%) that represents the RTO portion of the round-trip time (RTT) calculation. This percentage value must be an integer between 0 and 65535.
default

Resets the sctp-alpha to the default value of 5%.
Usage:

sctp-alpha is used in conjunction with other commands, such as the sctp-beta command, to determine the round-trip time (RTT) calculations. The Alpha parameter is used to manage load balancing within the SS7 environment for multi-homed peers.

IMPORTANT:

Before using this command to set a value or reset the default, you must disassociate the PSP instance with the no associate command. When you have modified your configuratioin with this command, then use the associate command to setup a new ASP association.

Example

Example
Set the SCTP RTO-Alpha value to 256% of the RTT calculation:

    sctp-alpha 256

sctp-beta

This stream control transmission protocol (SCTP) retransmission time out (RTO) parameter defines the RTO-Beta value.
Platform:

ASR 5000
Product:

SGSN
Privilege:

Security Administrator, Administrator
Syntax

    sctp-beta value

    default sctp-beta

value

Defines a percentage (%) that represents the RTO portion of the round-trip time (RTT) calculation. This percentage value must be an integer between 0 and 65535.
default

Resets the sctp-beta to the default value of 10%.
Usage:

Use this command in conjunction with other commands, such as the sctp-alpha command, to determine the round-trip time (RTT) calculations. The Beta parameter is used to manage load balancing within the SS7 environment for multi-homed peers.

IMPORTANT:

Before using this command to set a value, you must disassociate the PSP instance with the no associate command. When you have set the value with this command, then use the associate command to setup a new association.

Example

Example
Set the SCTP RTO-Alpha value to 512% of the RTT calculation:

    sctp-beta 512

sctp-checksum-type

This command selects the type of checksum algorithm to be used.
Platform:

ASR 5000
Product:

SGSN
Privilege:

Security Administrator, Administrator
Syntax

    sctp-checksum-type { adler32 | crc32 }default sctp-checksum-type

adler32

Selects the Adler-32 type of algorithm as a faster checksum function.
crc32

Selects the CRC-32, a slower but more reliable 32-bit cyclic redundancy check.
default

Resets the sctp-checksum-type to the default of CRC-32.
Usage:

Use this command to set which type of checksum algorithm the SGSN is to use to validate SCTP packets.

IMPORTANT:

Before using this command to set a value, you must disassociate the PSP instance with the no associate command. When you have set the value with this command, then use the associate command to setup a new association.

Example

Example
Set the checksum type for CRC32:

    sctp-checksum-type
    crc32

sctp-cookie-life

This command sets the SCTP valid cookie life.
Platform:

ASR 5000
Product:

SGSN
Privilege:

Security Administrator, Administrator
Syntax

    sctp-cookie-life valuedefault sctp-cookie-life

value

Sets the valid cookie life value in increments of 100 milliseconds. The range is 50 to 1200 .
default

Resets the sctp-cookie-life value to the default, 600 (= .6 seconds).
Usage:

Use this command to set the SCTP cookie life.

IMPORTANT:

Before using this command to set a value, you must disassociate the PSP instance with the no associate command. When you have set the value with this command, then use the associate command to setup a new association.

Example

Example
Set the SCTP cookie life to 1 second (1000 milliseconds):

    sctp-cookie-life 1000

sctp-init-rwnd

This command sets the size of the SCTP receiver window .
Platform:

ASR 5000
Product:

SGSN
Privilege:

Security Administrator, Administrator
Syntax

    sctp-init-rwnd window_sizedefault sctp-init-rwnd

window_size

Sets an integer to configure the window size. The range is 32768 to 1048576.
default

Resets the sctp-init-rwnd window size to the default, 1048576.
Usage:

Use this command to set the receiver window size in the configuration. Configuring this parameter enables the SCTP client to send configured ‘sctp-init_rwnd’ as a_rwnd parameter in the INIT message. For the SCTP server, the INIT ACK will be populated with sctp-init_rwnd as a_rwnd parameter per RFC 4960.

The command enables the operator to configure a reduced priority for LinkManager Control messages, thereby giving Timer messages the highest priority. The Timer messages are retained at the highest priority and Data messages are kept at a lower priority.

IMPORTANT:

Before using this command to set a value, you must disassociate the PSP instance with the no associate command. When you have set the value with this command, then use the associate command to setup a new association.

Example

Example
Use the following command to set the SCTP window size to 32786:

    sctp-init-rwnd 32768

sctp-max-assoc-retx

This command sets the maximum number of datagram retransmissions to be associated with this peer server configuration.
Platform:

ASR 5000
Product:

SGSN
Privilege:

Security Administrator, Administrator
Syntax

    sctp-max-assoc-retx valuedefault sctp-max-assoc-retx

value

Defines the maximum number of datagram retransmissions for an association. The value must be an integer between 0 and 255.
default

Resets the default for sctp-max-assoc-retx to 10.
Usage:

Use this command to configure the maximum number of datagram retransmissions for an association. The endpoint will be declared unreachable after sctp-max-assoc-retx number of consecutive retransmissions to an endpoint on any transport address.

IMPORTANT:

Before using this command to set a value, you must disassociate the PSP instance with the no associate command. When you have set the value with this command, then use the associate command to setup a new association.

Example

Example
Set the maximum number to 3 datagram retransmissions:

    sctp-max-assoc-retx
    3

sctp-max-init-retx

This command sets the maximum number of retries to send the INIT datagram.
Platform:

ASR 5000
Product:

SGSN
Privilege:

Security Administrator, Administrator
Syntax

    sctp-max-init-retx valuedefault sctp-max-init-retx

value

Sets the maximum number of retries. This value must be an integer between 0 and 255.
default

Resets the default for sctp-max-init-retx to 5.
Usage:

Use this command to set the maximum number of retries the SCTP layer should make to send the INIT datagram to the peer to open an association.

IMPORTANT:

Before using this command to set a value, you must disassociate the PSP instance with the no associate command. When you have set the value with this command, then use the associate command to setup a new association.

Example

Example

    sctp-max-init-retx
     3

sctp-max-mtu size

This command sets the number of bytes that comprise the maximum MTU size.
Platform:

ASR 5000
Product:

SGSN
Privilege:

Security Administrator, Administrator
Syntax

    sctp-max-mtu-size
     valuedefault sctp-max-mtu-size

value

Sets the maximum number of bytes for the SCTP MTU size. This value must be an integer between 508 and 65535.
default

Resets the default for sctp-max-mtu-size to 1500 bytes.
Usage:

Use this command to configure the size of the MTU.

IMPORTANT:

Before using this command to set a value, you must disassociate the PSP instance with the no associate command. When you have set the value with this command, then use the associate command to setup a new association.

Example

Example
Set the maximum size of the MTU to 3000 bytes:

    sctp-max-mtu-size
     3000

sctp-max-out-strms

This command sets the maximum number of outgoing streams through the PSP going towards the peer server.
Platform:

ASR 5000
Product:

SGSN
Privilege:

Security Administrator, Administrator
Syntax

    sctp-max-out-strms max#_out_streamsdefault sctp-max-out-strms

default

Resets the SGSN’s sctp-max-out-strms value to the default of 16.
max#_out_streams
Usage:

Use this command to balance the stream throughput from the PSP to the peer server. The value for this command is used to validate the incoming packets in the SCTP layer.

IMPORTANT:

Before using this command to set a value, you must disassociate the PSP instance with the no associate command. When you have set the value with this command, then use the associate command to setup a new association.

Example

Example
Set a maximum SCTP out streams to 12:

    sctp-max-out-strms
    12

Set a maximum SCTP out streams to the default of 16 streams:

    default sctp-max-out-strms

sctp-max-path-retx

This command sets the maximum number of datagram retransmissions for this path.
Platform:

ASR 5000
Product:

SGSN
Privilege:

Security Administrator, Administrator
Syntax

    sctp-max-path-retx
     valuedefault sctp-max-path-retx

value

Sets the maximum number of datagram retransmission to a destination transport address. This value must be an integer from 0 to 255.
default

Resets the sctp-max-path-retx default to 5.
Usage:

Use this command to set the maximum number of datagram retransmissions to a destination transport address. The destination transport address will be declared unreachable after the SGSN exhausts the sctp-max-path-retx number of consecutive retransmissions to a destination transport address.

Depending upon network conditions, lower values typically means faster detection of SCTP-Path failure.

IMPORTANT:

Before using this command to set a value, you must disassociate the PSP instance with the no associate command. When you have set the value with this command, then use the associate command to setup a new association.

Example

Example

    sctp-max-path-retx
     10

sctp-rto-initial

This command sets the initial retransmission timeout for the SCTP.
Platform:

ASR 5000
Product:

SGSN
Privilege:

Security Administrator, Administrator
Syntax

    sctp-rto-initial
     valuedefault sctp-rto-initial

default

Resets the system to the sctp-rto-initial default of 30 (3 seconds).
value

The value must be an integer between 1 and 50.
Usage:

IMPORTANT:

Before using this command to set a value, you must disassociate the PSP instance with the no associate command. When you have set the value with this command, then use the associate command to setup a new association.

Use this command to define the initial retransmission timer.

The value set for sctp-rto-initial should be greater than or equal to the minimum value set with sctp-rto-min (sctp-rto-initial=> sctp-rto-min).

The value set for sctp-rto-initial should be less than or equal to the maximum value set with sctp-rto-max (sctp-rto-initial <= sctp-rto-max).

Example

Example

    sctp-rto-initial  240

sctp-rto-max

This command sets the maximum retransmission timeout value for the SCTP.
Platform:

ASR 5000
Product:

SGSN
Privilege:

Security Administrator, Administrator
Syntax

    sctp-rto-max  valuedefault sctp-rto-max

default

Resets the system to the sctp-rto-max default of 600 (60 seconds).
value

Set the maximum retransmission timeout value in increments of 100 milliseconds (0.1 seconds) and the value must be an integer between 5 and 1200.
Usage:

IMPORTANT:

Before using this command to set a value, you must disassociate the PSP instance with the no associate command. When you have set the value with this command, then use the associate command to setup a new association.

Use this command to configure the maximum time for retransmissions.

The value set for sctp-rto-max should be greater than or equal to the value set for sctp-rto-initial (sctp-rto-max => sctp-rto-initial).
Example:
The following sets the timeout for 45 seconds:

    sctp-rto-max  450

sctp-rto-min

This command sets the minimum retransmission timeout (RTO) value for the SCTP.
Platform:

ASR 5000
Product:

SGSN
Privilege:

Security Administrator, Administrator
Syntax

    sctp-rto-min [ units-10ms ] valuedefault sctp-rto-min

default

Resets the sctp-rto-min to the default of 10 (1 second).
units-10ms

Including this keyword, before entering a value, enables configuration with finer granuality - in 10 millisecond units.
value

If the units-10ms keyword is included, then set the timeout in increments of 10 milliseonds. The value must be an integer between 1 and 500.

If the units-10ms keyword is not included then set the timeout in increments of 100 milliseconds. The value must be an integer between 1 and 50.
Usage:

IMPORTANT:

Before using this command to set a value, you must disassociate the PSP instance with the no associate command. When you have set the value with this command, then use the associate command to setup a new association.

Use this command to set the minimum time for retransmission before timeout.

The value set for sctp-rto-min should be less than or equal to the value set for sctp-rto-initial (sctp-rto-min <= sctp-rto-initial)
Example:
The following sets the timeout for 2 seconds:

    sctp-rto-min 20

sctp-sack-frequency

This command sets the frequency of transmission of SCTP selective acknowledgements (SACK).
Platform:

ASR 5000
Product:

SGSN
Privilege:

Security Administrator, Administrator
Syntax

    sctp-sack-frequency [ units-10ms ] valuedefault sack-frequency

value

Sets the maximum number of datagrams to be received prior to sending a SACK to the peer. The value must be an integer between 1 and 5.
default

Resets the sctp-sack-frequency default value of 2.
Usage:

IMPORTANT:

Before using this command to set a value, you must disassociate the PSP instance with the no associate command. When you have set the value with this command, then use the associate command to setup a new association.

Use this command to set the maximum number of datagrams to be received before a SACK must be sent to the peer. The sctp-sack-frequency is used in conjunction with the sctp-sack-period to control the generation of SACK, depending on which one occurs first.

Example

Example

    sctp-sack-frequency
     3

sctp-sack-period

This command sets the delay before sending an SCTP selective acknowledgement (SACK).
Platform:

ASR 5000
Product:

SGSN
Privilege:

Security Administrator, Administrator
Syntax

    sctp-sack-period [ units-10ms ] valuedefault sack-period

units-10ms

Including this keyword, before entering a value, enables configuration with finer granuality - in 10 millisecond units.
value

If the units-10ms keyword is included, then set the timeout in increments of 10 milliseonds. The value must be an integer between 0 and 50.

If the units-10ms keyword is not included then set the timeout in increments of 100 milliseconds. The value must be an integer between 0 and 5.
default

Resets the system to the sctp-sack-period default value, 2 (=200 milliseconds).
Usage:

Use this command to set the time the SCTP waits to send a SACK.

IMPORTANT:

Before using this command to set a value, you must disassociate the PSP instance with the no associate command. When you have set the value with this command, then use the associate command to setup a new association.

Example

Example

    sctp-sack-period  3

sctp-suppress-alarm

This command enables/disables the suppression of alarms for SCTP path failure between two peer endpoints.
Platform:

ASR 5000
Product:

SGSN
Privilege:

Security Administrator, Administrator
Syntax

    [ no ] sctp-suppress-alarm
    path-failure self-end-point-address orig_ipv4_addresspeer-end-point-address peer_ipv4_address

no

Disables the pre-configured alarm suppression for SCTP path failure.
path-failure

This keyword specifies that the alarm suppression is for SCTP path failure between two peer nodes.
self-end-point-address orig_ipv4_address

This keyword specifies the IP address of the originating endpoint.

orig_ipv4_address is the IP address of originating endpoint in IPv4 dotted decimal notation.
peer-end-point-address peer_ipv4_address

This keyword specifies the IP address of the peer endpoint.

peer_ipv4_address is the IP address of peer endpoint in IPv4 dotted decimal notation.
Usage:

Use this command to configure the path failure alarm suppression. This command ignores the alarms generated on SCTP path failure.

IMPORTANT:

Before using this command to set a value, you must disassociate the PSP instance with the no associate command. When you have set the value with this command, then use the associate command to setup a new association.
Example:
The following command suppresses the path failure alarms occurred in SCTP path between originating peer address 1.2.3.4 and peer endpoint 6.7.8.9:

    sctp-suppress-alarm
    path-failure self-end-point-address 1.2.3.4 peer-end-point-address 6.7.8.9

timeout

This command sets the times for various timeout timers.
Platform:

ASR 5000
Product:

SGSN
Privilege:

Security Administrator, Administrator
Syntax

    timeout {m3ua-periodic-dest-audit dest_timeout | sctp-bundle bundle_time | sctp-heart-beat hrt_bt_timeout}default timeout sctp-heart-beat

default

Resets the system to the default value for the SCTP heartbeat interval.
m3ua-periodic-dest-audit dest_timeout

Sets the period (in increments of seconds) between the DAUD messages while auditing a destination state.

dest_timeout: Must be an integer from 1 to 65535. Default is 2.
sctp-bundle bundle_time

Enables SCTP bundling and sets the SCTP bundle timeout value in incremenets of 100 milliseconds. SCTP bundling provides better bandwidth utilization and less traffic, however, there is a 100 millisecond packet transmission delay.

IMPORTANT:

Peer end should also be configured to support SCTP bundling.

Default: SCTP bundling is disabled.

bundle_time : Enter an integer from 1 to 65535.
sctp-heart-beat hrt_bt_timeout

Sets the number of seconds in the SCTP heart-beat timer

hrt_bt_timeout: This value is an integer between 1 and 300. Default is 30.
Usage:

Use this command to configure timers. Repeat the command with each of the keywords to set values for each.

IMPORTANT:

Before using this command to set a value, you must disassociate the PSP instance with the no associate command. When you have set the value with this command, then use the associate command to setup a new association.
Example:

    timeout m3ua-periodic-dest-audit 120