Nortel Networks NN43001-563 - Manual (Page 139)

Implement QoS in IP networks 139
Time-of-Day voice routing
Other important objectives associated with IP Trunk 3.01 (and later) network
translations and route list blocks are as follows:
1. Make IP Trunk 3.01 (and later) the first-choice, least-cost entry in the
Route List Block.
2. Use Time-of-Day (ToD) scheduling to block voice traffic to the IP Trunk
3.01 (and later) route during peak traffic periods on the IP data network
when degraded QoS causes all destination IP Trunk 3.01 (and later)
nodes to be in fallback mode.
The proper time to implement either setting is described as follows:
1. Make the IP Trunk 3.01 (and later) the first-choice, least-cost entry in
the route list block.
An IP Trunk 3.01 (and later) route should be configured with a higher
priority (lower entry number) than the fallback route in the LD 86 Route
List Blocks (RLB) of the ESN configuration. All calls to the target
destination with VoIP capability will try the IP route first before falling
back to traditional circuit-switched network.
2. Turn off the IP Trunk 3.01 (and later) route during peak traffic periods on
the IP data network.
Based on site data, if fallback routing occurs frequently and consistently
for a data network during specific busy hours; for example, every
Monday 10-11 a.m., and Tuesday 2-3 p.m. These hours should be
excluded from the RLB to maintain a high QoS for voice services. By not
offering voice traffic to a data network during known peak traffic hours,
the incidence of conversation with marginal QoS can be minimized. This
technique reduces some of the cost savings associated with using IP
Trunk 3.01 (and later) and should only be utilized if other methods of
improving the IP network QoS are not possible.
The time schedule is a 24-hour clock which is divided up the same way
for all 7 days. Basic steps to program ToD for IP Trunk 3.01 (and later)
routes are as follows:
a. Go to LD 86 ESN data block to configure the Time-of-Day Schedule
(TODS) for the required ITG control periods.
b. Go to LD 86 RLB and apply the TODS on/off toggle for that route list
entry associated with an IP Trunk 3.01 (and later) route.
3. Use the traditional PSTN for modem traffic.
IP Trunk 3.01 (and later) does not support modem traffic except Group
3 fax. Routing controls must be configured to route modem traffic over
circuit-switched trunks instead of over IP Trunk 3.01 (and later).
Nortel Communication Server 1000
IP Trunk Fundamentals
NN43001-563 01.01 Standard
Release 5.0 30 May 2007
Copyright © 2007, Nortel Networks
.