Avaya S8700 Maintenance Manual page 1963

PKT-INT (Packet Interface)
PKT-INT Interchange
In earlier G3r systems, PKT-INT interchange was an integral part of an SPE
interchange. In S8700 Multi-Connect, PKT-INT interchange is independent of
media server interchange (that is, a PKT-INT interchange can occur without a
media server interchange and vice versa). In S8700 Multi-Connect, the active
media server's packet control driver (PCD) has sockets to both active and
standby IPSIs and exchanges heartbeats with both. The active PCD is not only
responsible for bringing up the active PKT-INT but also responsible for bringing up
the standby PKT-INT into the standby mode. This is different than the current G3r
where the standby PCD brings up the standby PKT-INT into the standby mode.
The standby PCD also has sockets to both active and standby IPSIs and
exchanges heartbeats with both. The standby PCD only talks to the IPSI SIM and
does not communicate with the PKT-INTs. In the G3r systems, the active media
server communicated with the standby media server via the SMM to perform
maintenance activities on the standby PKT-INT. In S8700 Multi-Connect, the
active media server communicates directly with both active and standby PKT-INTs
and performs maintenance activities on both PKT-INTs without the standby media
server getting involved.
Earlier G3r PKT-INT duplication relied on the duplication hardware to
automatically duplicate and write each command from the processor into both the
active and standby PKT-INT's dual-port RAMs. The standby PKT-INT was always
up-to-date with the state of every link terminated by the active PKT-INT. On
S8700 Multi-Connect, there is no dedicated hardware to keep the standby
PKT-INT up-to-date. Instead, the PCD refreshes the standby PKT-INT prior to an
interchange.
Executing a PKT-INT Interchange
There are two ways to interchange PKT-INTs, spontaneous and planned.
1. A spontaneous interchange is usually caused by a fault, and:
2. A planned interchange can be requested by Services' personnel or by
software for maintenance or periodic testing.
The active media server's PCD has socket connections to both active and
standby IPSIs. Media server interchange and IPSI interchange are independent
of each other. IPSIs in an PN can be interchanged independently of IPSIs in other
PNs.
555-233-143
Stable calls are retained.
LAP-D links are restarted.
Some data may be lost.
LAP-D links are migrated from the active to the standby PKT-INT.
No data is lost during the interchange.
Issue 1 May 2002 8-1241