SGTP Service Configuration Mode Commands

SGTP Service Configuration Mode Commands
 
The SGSN GPRS Tunneling Protocol (SGTP) Service configuration mode provides the configuration of GTP-C and GTP-U related parameters.
[<ctx_name>]hostname(config-sgtp-service)#
note_smallImportant: The commands or keywords/variables that are available are dependent on platform type, product version, and installed license(s).
direct-tunnel-disabled-ggsn
This command makes it possible for the operator to disable direct tunneling on the basis of a GGSN.
Product
SGSN
Privilege
Security Administrator, Administrator
Syntax
direct-tunnel-disabled-ggsn IPv4/IPv6_address
no direct-tunnel-disabled-ggsn [ IPv4/IPv6_address ]
no
Deletes the direct-tunnel-disabled-ggsn configuration which results in re-enabling direct tunneling to the GGSN.
•
Including an IPv4 or IPv6 address for a specific GGSN, re-enables direct tunneling for that specific GGSN.
•
Excluding any IPv4 or IPv6 address from this command removes all direct-tunnel-disabled-ggsn definitions from the SGTP service configuration.
Usage
By default, GGSNs and RNCs are assumed to be capable of direct tunneling.
This command disables direct tunneling for a specified GGSN. The command can be repeated to disable direct tunneling for multiple GGSNs, thereby creating a ‘disabled GGSN’ list. Checking for a direct-tunnel-disabled GGSN is actually the last step in the PDP Activation procedure.
Restricting direct tunneling by a GGSN for an entire APN would be configured with the appropriate command in the APN profile configuration mode.
Restricting direct tunneling at the RNC level would be configured with the appropriate command in the IuPS service configuration mode.
This command can only be used if:
•
The Direct Tunnel license has been purchased and applied.
•
The Direct Tunnel feature is appropriately enabled via configurations of the IMEI profile and/or the Call-Control and APN profiles.
•
The RNC does not restrict direct tunnel.
•
The subscriber is not requesting CAMEL services.
Example
Use the following command to disable direct tunnel for the GGSN with the IP address of 141.21.4.20:
direct-tunnel-disabled-ggsn 141.21.4.20
disable-remote-restart-counter-verification
This command disables the SGSN’s default behavior for verification of the remote peer’s (GGSN) restart counter change values.
Product
SGSN
Privilege
Security Administrator, Administrator
Syntax
disable-remote-restart-counter-verification
[ default | no ] disable-remote-restart-counter-verification
default
Enables the default behavior for verification of the GGSN’s restart counter change values.
no
Disables the command configuration and enables the default behavior of verification.
Usage
This command disables the default behavior used to minimize PDP deactivations resulting from path failure detection due to erroneous restart counter change messages.
With the execution of this command, the SGSN stops verifying restart counters received in Create PDP Context Response or Update PDP Context Response or Update PDP Context Request (CPCR, CPCR, and UPCQ) messages. When the SGSN detects GTP-C path failure between the SGSN and the GGSN, the SGSN assumes PDP sessions at the GGSN are lost and the SGSN deactivates those PDP sessions towards the UE with an indication that the UE should activate the PDP session again. Potentially, this scenario could cause unnecessary traffic increases within the operator’s network.
The SGSN default behavior provides the ability to manage GTP-C path failures detected as a result of spurious restart counter change value messages received from the GGSN. With the default behavior, path failure detection is based on receipt of restart counter change values in CPCR, CPCR, and UPCQ messages. The session manager informs the SGTPC manager about a changed restart counter value. The SGTPC manager verifies the PDP context status by performing an echo request and echo response with the GGSN. Only then is the path failure confirmed if the echo response contains a new restart counter value. Then the SGTPC manager informs all session managers about the path failure and the session managers begin deactivation of the PDP contexts.
Related commands:
•
max-remote-restart-counter-change, also part of the SGTP service configuration mode, allows the operator to set a maximum variance between stored and received values for restart counter changes coming from the GGSN.
•
pdp-deactivation-rate, in the SGSN Global configuration mode, allows the operator to modify the rate the SGSN deactivates PDP connections when GPT-C path failure is detected.
•
ignore-remote-restart-counter, also part of the SGTP service configuration mode.
Example
Disable the default behavior and stop verification with echo request/response process:
disable-remote-restart-counter-verification
Use either of the following commands to enable the default verification behavior:
no disable-remote-restart-counter-verification
default disable-remote-restart-counter-verification
end
Exits the configuration mode and returns to the Exec mode.
Product
SGSN
PDG/TTG
Privilege
Security Administrator, Administrator
Syntax
end
Usage
Changes the mode to the Exec mode.
exit
Exits the SGTP Service configuration mode and returns to the Context configuration mode.
Product
SGSN
PDG/TTG
Privilege
Security Administrator, Administrator
Syntax
exit
Usage
Return to the previous mode.
ggsn-fail-retry-timer
This command sets the amount of time that a GGSN will be unavailable.
Product
SGSN
Privilege
Security Administrator, Administrator
Syntax
ggsn-fail-retry-timer value
no ggsn-fail-retry-timer
no
Removes the timer setting and disables the Local DNS feature.
value
Defines the amount of time, in seconds, that the GGSN is to be considered unavailable.
Enter an integer from 60 to 600. Default is 300.
Usage
Setting this timer to a valid value enables the Local DNS feature - described in the SGSN Administration Guide. Setting this timer marks a GGSN in the primary GGSN pool as unavailable for PDP context creation and causes the SGSN to forward a PDP Context Activation Request to a remote pool GGSN, identified via a local (on the SGSN) DNS check. Marking a GGSN unavailable can be done if there is a reason to believe the GGSN is unavailable; for example, lack of response to GTP messages. Marking a GGSN as unavailable is usually done for a limited period to allow the GGSN time to recover.
Example
Enable the Local DNS feature and mark the GGSNs in the primary pool as unavailable for 4 minutes (240 seconds):
ggsn-fail-retry-timer 240
gn-delay-monitoring
This command configures monitoring of Gn/Gp interface to check for the delay of packets between the SGSN and the GGSN.
Product
SGSN
Privilege
Security Administrator, Administrator
Syntax
gn-delay-monitoring [ num-delay number_delayed | num-no-delay-for-clear number_normal | tolerance-seconds number_seconds ]
default gn-delay-monitoring [ num-delay | num-no-delay-for-clear | tolerance-seconds ]
no gn-delay-monitoring
default
Resets the specified parameter to the default value.
no
Disables Gn/Gp monitoring for delayed GTP-C packets.
num-delay number_delayed
Defines the number of response messages, coming from the GGSN, that can be delayed (delay time defined by tolerance-seconds parameter) before the delay is flagged to generate an SNMP trap.
number_delayed: Enter an integer from 1 to 500, default is 30.
num-no-delay-for-clear number_normal
Defines the number of consecutive response messages, coming from the GGSN, that must be received without delay (in normal response time) to clear the flag towards the GGSN.
number_normal: Enter an integer from 1 to 500, default is 15.
tolerance-seconds number_seconds
Defines the 'normal' number of seconds the SGSN should wait for a response from the GGSN. After this time, the response would be considered 'delayed'.
number_seconds: Enter an integer from 1 to 20, default is 4 seconds.
note_smallImportant: The value for this parameter should be less than the value set for the retransmission-timeout parameter of the gtpc command, also in this configuration mode.
Usage
With this command, the SGSN can monitor the control plane packet delay for GTP-C signaling messages on the SGSN’s Gn/Gp interface towards the GGSN. If the delay crosses this configurable threshold, an alarm will be generated to prompt the operator.
A delay trap is generated when the GGSN response to an ECHO message request is delayed more than a configured amount of time and for a configured number of consecutive responses. When this occurs, the GGSN will be flagged as experiencing delay.
A clear delay trap is generated when successive ECHO Response (number of successive responses to detect a delay clearance is configurable), are received from a GGSN previously flagged as experiencing delay.
This functionality can assist with network maintenance, troubleshooting, and early fault discovery.
Example
Enable Gn/Gp monitoring for GTP-C packets that arrive from the GGSN with a delay greater than 5 seconds:
gn-delay-monitoring tolerance-seconds 5
gtpc
Configure the GPRS Tunneling Protocol Control (GTP-C) settings for the SGTP service.
Product
SGSN
MME
PDG/TTG
Privilege
Security Administrator, Administrator
Syntax
gtpc { bind address ip_address | dns-sgsn context cntxt_name | echo-interval seconds | guard-interval seconds | ignore response-port-validation | ip qos-dscp <dscp_marking> | max-retransmissions num | retransmission-timeout seconds | send { common flags | rab-context | target-identification-preamble } }
no gtpc { bind address ip_address | dns-sgsn context cntxt_name | echo-interval seconds | send { common- flags | rab-context | target-identification-preamble } }
default gtpc { echo-interval | guard-interval | ignore response-port-validation | ip qos-dscp | max-retransmissions | retransmission-timeout | send { common-flags | rab-context | target-identification-preamble } }
no
Disables the configured GTPC setting.
default
Resets the specified parameter to its default value.
bind address ip_address
Binds SGTP service to the IP address of the interface.
The bind address for the gtpc and gtpu commands should be the same.
ip_address: Enter a standard dotted-quad IPv4 address.
dns-sgsn context cntxt_name
Enter a string of 1 to 79 alphanumeric characters to identify the context.
echo-interval seconds
Configures the duration between echoes.
seconds: Enter an integer from 0 through 3600.
Default: 60
guard-interval seconds
Configures the interval (in seconds) for which the SGTP maintains responses sent to SGSN. This optimizes the handling of retransmitted messages. This value should be configured to be greater than the SGSN's configuration for max-retries multiple by retry-interval.
seconds: Enter an integer from 10 to 3600.
Default: 100
ignore response-port-validation
This keyword instructs the SGSN to ignore the response port validation.
For the SGSN to process incoming GTP responses to an incorrect port,
•
this keyword must be entered, and
•
the same bind address must be configured for GTPC and GTPU in the SGTP service.
Default: disabled. To reset the default for this parameter, you must enter the following command: no gtpc ignore response-port-validation.
ip qos-dscp <dscp_marking>
Configures the diffserv code point marking to be used when sending GTP-C messages originating from the session manager and SGTPC manager.
<dscp_marking>: Enter one of the following values:
•
af11: Marks traffic as Assured Forwarding 11 PHB (high throughput data)
•
af12: Marks traffic as Assured Forwarding 12 PHB (high throughput data)
•
af13: Marks traffic as Assured Forwarding 13 PHB (high throughput data)
•
af21: Marks traffic as Assured Forwarding 21 PHB (low latency data)
•
af22: Marks traffic as Assured Forwarding 22 PHB (low latency data)
•
af23: Marks traffic as Assured Forwarding 23 PHB (low latency data)
•
af31: Marks traffic as Assured Forwarding 31 PHB (multimedia streaming)
•
af32: Marks traffic as Assured Forwarding 32 PHB (multimedia streaming)
•
af33: Marks traffic as Assured Forwarding 33 PHB (multimedia streaming)
•
af41: Marks traffic as Assured Forwarding 41 PHB (multimedia conferencing).
•
af42: Marks traffic as Assured Forwarding 42 PHB (multimedia conferencing)
•
af43: Marks traffic as Assured Forwarding 43 PHB (multimedia conferencing)
•
be : Designates use of Best Effort forwarding PHB. This is the default value.
•
ef : Designates use of Expedited Forwarding PHB
Default: be (best effort)
max-retransmissions num
Configures the maximum number of retries for packets.
num: Enter an integer from 0 to 15.
Default: 4
retransmission-timeout seconds
Configures the control packet retransmission timeout in GTP, in seconds.
seconds: Enter an integer value from 1 through 20.
Default: 5
send { common-flags | rab-context | target-identification-preamble }
common-flags : This option configures the SGTP service to include or exclude the common flags IE during an Inter-SGSN RAU. When selected, the default is to send the common flags IE.
rab-context : This option configures the SGTP service to include/exclude the radio access bearer (RAB) context IE in SGSN ‘context response’ message during Inter-SGSN Routing Area Update procedure. Default is to send the RAB context IE.
Default: RAB context IE.
target-identification-preamble : This option configures the SGTP service to include the preamble byte in the target-id of Relocation Requests that it sends. By default, the preamble is not included.
note_smallImportant: Sending of common flags must be enabled to configure dual PDP type (IPv4v6) addressing with the dual-address-pdp command in the SGSN global configuration mode.
Usage
Use this command to configure GTP-C settings for the current SGTP service.
Example
Following command excludes the radio access bearer (RAB) context IE in the SGSN Context Response message during the inter-SGSN RAU procedure:
no gtpc send rab-context
Configure the SGSN to send common flags with all GTP-C messages:
gtpc send common-flags
gtpu
This command configures the GPRS Tunneling Protocol user data plane parameters (GTP-U) for this SGTP service.
Product
SGSN
PDG/TTG
Privilege
Security Administrator, Administrator
Syntax
gtpu { bind address ip_address | echo-interval | max-retransmissions | retransmission-timeout } +
no gtpu { bind | echo-interval }
default gtpu { echo-interval | max-retransmissions | retransmission-timeout }
no
Removes the configuration for the specified parameter from the current SGTP service configuration.
default
Resets the specified GTP-U parameter to its factory default.
bind address ip_address
Defines the GTP-U Gn interface IP address that binds to this SGTP service.
The gtpu and the gtpc commands should be configured with the same bind address.
ip_address: Enter a standard dotted-quad IPv4 address.
echo-interval seconds
Configures the echo interval.
seconds: Enter an integer from 60 through 3600.
Default: 60
max-retransmissions num
Configures the maximum number of retries for retransmitting packets.
num: Enter an integer from 0 through 15.
Default: 4
retransmission-timeout seconds
Configures the retransmission timeout of packets, in seconds.
seconds: Enter an integer from 1 through 20.
Default: 5
Usage
Use this command to configure the GTP-U settings for the SGTP service.
Example
Set the GTPU echo-interval for 5 seconds:
gtpu echo-interval 5
ignore-remote-restart-counter-change
With the inclusion of the disable-remote-restart-counter-verification command, this command has been deprecated.
max-remote-restart-counter-change
Use this command to set a restart counter change window to avoid service deactivations and activations that could cause large bursts of network traffic if the restart counter change messages from the GGSN are erroneous
Product
SGSN
Privilege
Security Administrator, Administrator
Syntax
max-remote-restart-counter-change variance
default max-remote-restart-counter-change
default
If this keyword is used or if a variance window is not configured, then the default value will be 255 and the default behavior of the SGSN will be to detect a restart on any change.
variance
Set a number (an 8-bit value) that will define the variance range for restart counter change values compared between the SGSN's stored value and the value received in messages from the GGSN. Valid entry is an integer from 1 to 255; default is 255.
Value of 32 is recommended as it provides a sufficient window to allow the SGSN to handle delayed messages with old restart counters.
Usage
When the SGSN detects GTP-C path failure between the SGSN and the GGSN, the SGSN assumes PDP sessions at the GGSN are lost and the SGSN deactivates corresponding PDP sessions towards the UE with an indication that the UE should activate the PDP session again. Detection is based on receipt of restart counter change values in Create PDP Context Response or Update PDP Context Response or Update PDP Context Request (CPCR/UPCR/UPCQ) messages. Potentially, this scenario can cause major traffic increases within the operator's network. It is possible that the messages received from the GGSN are spurious.
The SGSN default behavior provides the ability to verify possible GTP-C path failures detected as a result of spurious restart counter change messages received from the GGSN. With the default behavior, the session manager informs the SGTPC manager about a changed restart counter value. The SGTPC manager responds by verifying the PDP context status by performing an Echo Request / Echo Response with the GGSN. If the Echo Response includes a new restart counter change value, then the session manager considers the path failure confirmed and begins the PDP context deactivation sequence.
Use this command to avoid unnecessary path failures and deactivations by setting a restart counter change value ‘window’ or range of values. With this window, the SGSN only accepts linearly increasing values for restart counter change values that are within the specified range of accepted changes before the SGTPC manager verifies. For example, if the allowed window for restart counter change value is set to 32 and the last learnt restart counter change value from the GGSN is 15, then the SGSN should detect a restart only if the new restart counter value is between 16 and 47 (range of 32) and then the SGSN would verify with the Echo Request/Response. If the received restart counter change value was 200 and the current learnt value was 15 with a window of 32, then the 200 would be ignored as a spurious value.
Also, use this command to set a restart counter change values window to avoid possible 'race conditions' (as defined in 3GPP TS 23.007 v8.7.0) where a new message arrives prior to an older message. This 'race condition' occurs when the SGSN's stored restart counter value for the GGSN is larger than the restart counter value received in the messages received from the GGSN.
Related commands:
•
disable-remote-restart-counter-verification - also part of the SGTP service configuration mode, this command allows the operator to disable the default behavior.
•
pdp-deactivation-rate, in the SGSN Global configuration mode, this allows the operator to modify the rate the SGSN deactivates PDP connections when GPT-C path failure is detected.
•
ignore-remote-restart-counter, also part of the SGTP service configuration mode.
Example
Use the following command to configure an allowed restart counter change value window of 32:
max-remote-restart-counter-change 32
mbms
Enables / disables the Multimedia Broadcast Multicast Service
note_smallImportant: The mbms command and parameter-configuring keywords are under development for future release and should not be used or included in your configuration at this time.
Product
SGSN
Privilege
Security Administrator, Administrator
Syntax
mbms
Usage
path-failure
This command specifies the method for determining if path failure has occurred.
Product
SGSN
Privilege
Security Administrator, Administrator
Syntax
path-failure detection-policy gtp type
[ default | no ] path-failure detection-policy
default
Resets the specified path failure parameter to default.
no
Deletes the path-failure definition from the configuration.
detection-policy gtp type
Specifies the policy to be used, value options include:
•
echo - When set to ‘echo’, path failure is detected when the retries of echo messages time out.
•
non-echo - When set to ‘non-echo’, path failure is detected when the retries of non-echo messages time out.
Default: echo (for both GTPC and GTPU)
Usage
Use this command to define the policy to detect gtp path failure.
Example
Set echo as the polity detection type:
path-failure detection-policy gtp echo
pool
This command enables the default SGSN functionality for (flex) pooling and enables inclusion of the configured pool hop-counter count in new SGSN context/identify request messages.
Product
SGSN
Privilege
Security Administrator, Administrator
Syntax
pool { default-sgsn | hop-counter count }
no pool { default-sgsn | hop-counter }
default pool hop-counter
no
Disables the default SGSN pooling functionality or removes the SGSN pool hop-counter IE from the GTP Identity/context requests.
default
Removes the SGSN pool hop-counter IE from the GTP Identity/context requests.
default-sgsn
Enables default SGSN pooling functionality.
hop-counter count
Enables and configures the SGSN pool hop-counter to set the number of hops and to include the configured count in the new SGSN Context Requests or the new SGSN Identify Requests.
If default-sgsn is enabled, then any messages relayed will have the default value of 4 for the counter if the message does not include this hop-counter ID.
count: Enter an integer from 1 to 255.
Default: 4
Usage
Use this command to enable the default flex functionality without exposing the pool (flex) structure. This functionality provides a means for SGSNs outside of the pool to reach a pooled SGSN on the basis of its NRI.
Once the pooling has been enabled. Repeat the command using the hop-counter keyword to enable inclusion of the hop-counter IE in SGSN context/identify request messages and to configure the count for the pooling hop-counter. If the SGSN is behaving as the ‘default SGSN’, this SGSN will forward (relay) requests with the hop-count included to the target SGSN.
Example
Enable the default pooling functionality which allows an outside SGSN to reach a pooled SGSN:
pool default-sgsn
Set the hop-count to be included in messages to 25:
pool hop-count
 
 
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