Cisco Cisco Packet Data Gateway (PDG) Fehlerbehebungsanleitung
MSID and PCF Zone Based Call Redirection
▀ Overview
▄ Cisco ASR 5000 Series Enhanced Feature Configuration Guide
OL-22982-01
Overview
MSID and PCF zone based call redirection allows calls from a specific MSID or a specific PCF zone to be redirected to
an alternate PDSN. These features are only applicable to new calls; handoffs are accepted by the PDSN in all cases. If
the PDSN is in the process of starting up, the overload policy is applied before the zone/IMSI based call redirection.
Once the PDSN is ready to accept new calls, the zone/IMSI based call redirection policy is applied before the overload
policy. Upon receiving an RRQ from a PCF, the PDSN sends an RRP with the code 136 - Unknown PDSN Address.
an alternate PDSN. These features are only applicable to new calls; handoffs are accepted by the PDSN in all cases. If
the PDSN is in the process of starting up, the overload policy is applied before the zone/IMSI based call redirection.
Once the PDSN is ready to accept new calls, the zone/IMSI based call redirection policy is applied before the overload
policy. Upon receiving an RRQ from a PCF, the PDSN sends an RRP with the code 136 - Unknown PDSN Address.
MSID Based Call Redirection
The PDSN contains a table of MSIDs and the corresponding set of PDSNs to which the call should be redirected. It
allows the configuration of up to 16 wildcard MSIDs per PDSN service. The wildcard must be a single-digit match
represented by the ―$‖ character. For example, the MSID 847$$$$$$$$12$$ would match all MSIDs starting with 847
followed by any eight digits, followed by 12 and any two additional digits.
allows the configuration of up to 16 wildcard MSIDs per PDSN service. The wildcard must be a single-digit match
represented by the ―$‖ character. For example, the MSID 847$$$$$$$$12$$ would match all MSIDs starting with 847
followed by any eight digits, followed by 12 and any two additional digits.
When a new call arrives, the PDSN attempts to match the MSID with the configured list of wildcard MSIDs. If a match
is found, the call is redirected to one of the PDSNs by IP address using a weighted round-robin algorithm. If more than
one match is found, the algorithm selects the match with the longest matching prefix.
is found, the call is redirected to one of the PDSNs by IP address using a weighted round-robin algorithm. If more than
one match is found, the algorithm selects the match with the longest matching prefix.
PCF Zone Based Call Redirection
Groups of PDSNs maybe configured with a specific numbered zone. When a new call arrives, the PDSN checks the
PCF for a specified zone number. If the PCF matches the specified zone, the call is redirected to a PDSN within the
zone using a weighted round-robin algorithm. If the PCF from which the call arrived does not belong to a zone, or if no
PDSNs are configured for the specified zone, the call is not redirected. Similarly, if a zone is configured for a PCF
address and the current PDSN-service address is a member of that zone, the call is not redirected.
PCF for a specified zone number. If the PCF matches the specified zone, the call is redirected to a PDSN within the
zone using a weighted round-robin algorithm. If the PCF from which the call arrived does not belong to a zone, or if no
PDSNs are configured for the specified zone, the call is not redirected. Similarly, if a zone is configured for a PCF
address and the current PDSN-service address is a member of that zone, the call is not redirected.
Caution:
These two features introduce additional lookups in the call setup path and could impact the call setup
rate.
Important:
If both MSID and PCF zone based call redirection are configured, MSID based call redirection will
have a higher precedence.