Nortel Networks NN43001-314 - Manual (Page 334)

334 Basic Emergency Services When VO Logged Out
The call to PSAP occurs immediately after the set registers, requiring the
correct location information; This is not desired. Special handling may be
required, possibly by directly calling background LIS for the VOLO TN.
Active Call Fail Over
Interactions with Active Call Fail over can be considered under the following
possible scenarios:
• ELAN failure happens for less than 10 minutes:
— The ESA VOLO phone is on a call.
The call must remain up since TPS keeps the set registered till
10 minutes. The TN synchronization after ELAN goes up must be
completed without any errors.
— ESA VOLO phone is in Waiting to Callback and Awaiting Callback
status.
The ESTN VOLO timer can expire during this period, causing the
ESTN to be released. If the ELAN Signalling Server sends the TN
online for the logged out phone with the TN previously used, that
ESTN may already be assigned to another phone. The result can be
unpredictable.
To avoid this situation, the LTPS must move the phone to its original
logged out state, and allow the Call Server to release the ESTN
and its associated timer.
• ELAN/TLAN failure happens for more than 10 minutes when:
— The ESA VOLO phone is on a call.
As a result, the ACF timer or PSAP will release the call register. In
this case, the ESA VOLO timer should be removed. Nevertheless,
the active call should survive. The phone returns to its original
logged out state, but according to ACF feature, the TPS closes
the audio path if the phone goes on-hook or you press the release
button.
— ESA VOLO phone is in Waiting to Callback status.
This is the same as 2a case, when the phone looses it’s ESTN
info after reregistering and will go back to it’s original logged out
state. This needs additional implementation on Call Server to free
up reserved ESTN and it’s timer.
Context Sensitive Soft Keys
This will work for the original soft keys that came from Call Server, but there
are two extra callers and redial soft keys that are added on the TPS. It needs
an extra check on the TPS to prevent these two soft keys on a VOLO set.
Nortel Communication Server 1000
Branch Office Installation and Commissioning
NN43001-314 01.02 Standard
Release 5.0 20 June 2007
Copyright © 2007, Nortel Networks
.