Wan Route Bandwidth Engineering - Nortel 1000 Description, Installation And Operation Manual

The TRMB prompt in RDB does not have to be set to Yes for TAT or TRO
to work. The function of the TRMB prompt is to allow or disallow
tromboning caused by NARS/BARS mis-configuration. For example, Site A
has DSC of 4000 pointing to Site B. Site B has DSC of 4000 pointing back to
Site A. If a caller at Site A dials 4000, this can lead to the call orbiting
between the two sites. This is commonly referred to as the "Ping-Pong"
effect. Therefore, Nortel Networks recommends setting TRMB to NO.

WAN route bandwidth engineering

After the TLAN subnet traffic is calculated, determine the bandwidth
requirement for the WAN. In this environment, bandwidth calculation is
based on network topology and destination pairs.
Before network engineering can begin, obtain the following network data:
• A network topology and routing diagram.
• A list of the sites where the IP Trunk 3.01 (and later) nodes are to be
installed.
• List the sites with IP Trunk 3.01 (and later) traffic, and the codec and
frame duration (payload) to be used.
• Obtain the offered traffic in CCS for each site pair; if available, separate
voice traffic from fax traffic (fax traffic sent and received).
• In a network with multiple time zones, use the same real-time busy hour
varying clock hours) at each site that yields the highest overall network
traffic. Traffic to a route is the sum of voice traffic plus the larger of one
way fax traffic (either sent or received.
ITG engineering guidelines
IP Trunk Description, Installation, and Operation
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