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.
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.
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.
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.
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.
Configuring MSID
and PCF Zone Based Call Redirection
This section
describes the process of setting up MSID and PCF zone based call
redirection from the command line interface.
CAUTION:
Incorrect configuration
of the MSID and PCF Zone based Call Redirection features could result
in sessions failing to be established. For example, if PDSN1 is
configured to redirect sessions to PDSN2 while PDSN2 is configured
to redirect sessions to PDSN1, a loop is created in which all sessions
would fail to be connected. In addition, sessions will not be established
if the PDSN to which the sessions are being redirected is unavailable.
Configuring MSID
Based Call Redirection
To configure
MSID based call redirection, you must create a new policy that defines
a wildcard match list, a list of PDSNs to redirect to, and their
respective weights.
IMPORTANT:
Commands used in the
configuration samples in this section provide base functionality
to the extent that the most common or likely commands and/or
keyword options are presented. In many cases, other optional commands
and/or keyword options are available. Refer to the CDMA
Command Line Interface Reference for complete information regarding
all commands.
Configure MSID based
call redirection by applying the following example configuration:
configure
context <context_name>
pdsn-service <pdsn_service_name>
policy msid-match <msid_with_wildcards> redirect <address>
weight <weight_num>
<address2> weight <weight_num>...<address16> weight <weight_num>
end
Notes:
- You may repeat the policy msid-match command
as needed, to a maximum of 16 wildcard MSIDs per PDSN service.
Save your configuration
to flash memory, an external memory device, and/or a network location
using the Exec mode command save configuration. For
additional information on how to verify and save configuration files,
refer to the System Administration Guide and the CDMA
Command Line Interface Reference.
Configuring PCF
Zone Based Call Redirection
To configure
PCF zone based call redirection, you must create a new policy that
defines a zone match list, a list of PDSNs to redirect to, and their
respective weights.
IMPORTANT:
Commands used in the
configuration samples in this section provide base functionality
to the extent that the most common or likely commands and/or
keyword options are presented. In many cases, other optional commands
and/or keyword options are available. Refer to the CDMA
Command Line Interface Reference for complete information regarding
all commands.
To configure PCF zone
based call redirection:
-
Set parameters by
applying the following example configuration:
configure context <context_name> pdsn-service <pdsn_service_name> spi remote-address <pcf_ip_address> spi-number <number> secret
<secret> zone <zone_id> zone <zone_id2>...zone <zone_id32> policy pcf-zone-match <zone_number> redirect <address> weight <weight_num> <address2> weight <weight_num>...<address16>
weight <weight_num> endNotes:
You may repeat the spi remote-address <pcf_ip_address> spi-number <number> secret <secret> [ zone <zone_id> ] [ zone <zone_id2>... zone <zone_id32> ] command
as necessary. You can configure up to 32 PCF zones per PDSN service.
You may repeat the policy pcf-zone-match <zone_number> { redirect <address> } [ weight <weight_num> ] [ <address2> [ weight <weight_num> ]...<address16> [ weight <weight_num> ] ] command as
necessary, up to a maximum of 32 defined PCF zones and 16 defined
PDSNs per PDSN service.
-
Save your configuration
to flash memory, an external memory device, and/or a network
location using the Exec mode command save configuration.
For additional information on how to verify and save configuration
files, refer to the System Administration Guide and the CDMA Command
Line Interface Reference