Nortel Networks NN43001-106 - Manual (Page 500)

500 B34 Dynamic Loss Switching
Typically, there are different vintages of firmware in the field:
• hard-coded B34 firmware, which is hardcoded with country-specific
defaults, ignores B34 type 12 messages, and accepts (where applicable)
Short Line/Long Line configuration type 5 messages
• flexible B34 firmware with country-specific defaults, which is firmware
that is coded with country-specific defaults, accepts (where applicable)
Short Line/Long Line configuration type 5 messages, and accepts B34
type 12 messages which override any accepted Short Line/Long Line
configuration type 5 messages
• flexible B34 firmware with universal defaults, which is firmware that is
coded with a universal B34 loss value default, may or may not ignore
Short Line/Long Line configuration type 5 messages, and accepts B34
type 12 messages which override any accepted Short Line/Long Line
configuration type 5 messages
To obtain the full functionality of B34 Dynamic Loss Switching, only the two
flexible vintages of firmware can be used.
Every time a new connection is established, the following process is followed
to determine if and how to adjust the loss involved in the connection:
• the port type of the originator and terminator is determined, based on
the configurations of the originator and terminator, respectively
• this port type is used as a row index (originator) and column index
(terminator) into a connection matrix, to determine the following:
— whether to switch the pad in or out for the originator receive direction
whether to switch the pad in or out for the originator transmit direction
— whether to switch the pad in or out for the terminator receive direction
— whether to switch the pad in or out for the terminator transmit
direction
• a message conveying this information is then sent to the originator and
terminator, if they are affected port types.
The B34 Dynamic Loss Switching feature, configured on a system basis,
introduces flexibility in the loss values to be switched. Where previously
the loss values were hardcoded on the analog trunk cards, they are
now software-configurable on a per-system basis. The loss switching is
still controlled by a connection matrix defined for specific markets. This
matrix cannot be changed. The loss levels to be used are configured in a
base-level table and alternative-level table in LD 97. The base level table is
the same as the one implemented and used by the B34 Static Loss Plan
Downloading feature; the alternative level table is a parallel table configured
for the B34 Dynamic Loss Switching feature.
Nortel Communication Server 1000
Features and Services - Book 1 of 6 (A to B)
NN43001-106 01.04 Standard
Release 5.0 27 July 2007
Copyright © 2007, Nortel Networks
.