Avaya S8700 Series, Maintenance Manual

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Maintenance-Object Repair Procedures
555-233-143 8-1242 Issue 1 May 2002
Spontaneous PKT-INT Interchange
For S8700 Multi-Connect, the standby PKT-INT is not kept up-to-date with the
links terminated by the active PKT-INT. During a spontaneous interchange of
PKT-INTs, the standby PKT-INT is refreshed with the link information by the active
PCD and the standby PKT-INT is activated with a warm reset. As with G3r, a
spontaneous interchange of PKT-INTs may result in loss of some up-stream and
down-stream data.
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PCD maintains socket connections to the active and the standby PKT-INTs
(via the SIM).
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Media server sends control and data packets only to the active PKT-INT.
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Standby PKT-INT has no information about the LAP-D links.
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On a spontaneous interchange, the standby PKT-INT is “refreshed” by the
PCD. That means the LAT and the LCT are sent to the PKT-INT, and the
standby PKT-INT is made active by a warm interrupt.
Planned PKT-INT Interchange (Link Migration)
A planned interchange of PKT-INTs uses link migration to assure that no data is
lost during the interchange of PKT-INTs. On a planned interchange of PKT-INTs,
software initiates the link migration by sending commands to the active and
standby PKT-INTs to make a peer link between the PKT-INTs and to start the link
migration process. Down-stream and up-stream messages can be processed by
the PKT-INTs during the link migration process. As long as the PKT-INT
interchange has not been completed, PCD should continue to send down-stream
messages to the active PKT-INT. If a down-stream data packet is for a link that
has not yet been migrated over to the standby PKT-INT, the active PKT-INT
processes it and sends it out.
If a down-stream data packet is for a link that has already migrated over to the
standby PKT-INT, the peer link forwards the down-stream data packet to the
standby PKT-INT, and the standby PKT-INT processes it and sends it out.
Up-stream messages during migration are handled by both PKT-INTs as with the
down-stream messages. The PKT-INT that controls the link (the active PKT-INT if
the link has not yet been migrated, and the standby PKT-INT if the link has been
migrated) processes the up-stream data packet and sends it up to the PCD.
During the migration process, both the active and the standby PKT-INTs can send
up-stream messages to the PCD.
On G3r, during the migration process, the standby PKT-INT terminating a link
processes the up-stream packet and forwards it to the active PKT-INT which
sends it up to the PCD.