The PMIP MAG SSO
feature supports only the Cisco ASR 1000 Series Aggregation Services Routers
intrachassis (RP-to-RP) SSO, but not the interchassis (Cisco ASR1K-to-Cisco
ASR1K) SSO. The First Sign Of Life (FSOL) triggers that are supported on SSO
include DHCP proxy (where the iWAG acts as the DHCP proxy server) and DHCP
proxy plus unclassified MAC.
For more information
about ISSU, see the “Overview of ISSU on the Cisco ASR 1000 Series Routers”
section of the
Cisco ASR 1000 Series Aggregation Services Routers Software
Configuration Guide.
The process as part
of iWAG SSO handling PMIPv6 checkpoints to the standby RP the information that
is necessary to create a copy of the session on the standby RP. Such an
inactive copy of the session becomes active when the standby RP becomes active.
When an iWAG
mobility session with PMIPv6 tunneling is enabled using the SSO/ISSU feature,
the Cluster Control Manager on the active RP needs to wait for a few more
components, including the Policy, SSS, DHCP-SIP etc, to become ready before
checkpoint data collection, and polls these additional components for
checkpoint data during data collection. A very similar operation is performed
on the standby RP as well. Although such additional CPU consumption is per
session, it is not expected to be too heavy since processing in each of these
components should include the time spent on a few data structure lookups and
memory-copying operations.
Default IWAG
configuration enables IWAG SSO. No specific command is required for configuring
this feature.