Nortel Networks NN43001-563

Factors that effectthe real-time capacity 107

Nortel recommends that trafﬁc on a single card ITG-Pentium 24-port trunk

card node never exceed the following:

•5000 calls/hour – Gatekeeper-routed

•6000 calls/hour – non-Gatekeeper-routed

In a multi-card node, the various roles necessary in processing calls, such

as Leader card,DCHIP card, and Follower card, can be divided over multiple

cards. This ensures that no IP trunk card exceeds its real-time capacity.

The maximum number of cards one DCHIP card can support is limited

by the restriction of 382 TIE trunks for one D-Channel. Therefore, only

12 Media Cards 32-port or 16 ITG-Pentium 24-port trunk cards can be

supported by one DCHIP card.

Recommendation

Nortel recommends a node never exceed the ratio of 12 Media Card 32-port

trunk cards or 16 ITG-Pentium 24-port trunk cards to one Leader card.

A node has only one Leader card; however,more then one DCHIP card can

be provisioned. If a DCHIP card fails, all IP trunk cards with channels that

use that D-channel are out of service; the remaining IP trunk card channels,

though, do remain in service. This conﬁguration provides some redundancy

and less work for each DCHIP card.

In a multi-card node, do not havethe Leader function and DCHIP function

on the same IP trunk card, unless all voice channels are disabled on that

card. A Leader card needs to have voice channels provisioned on the IP

trunk card to receive provisioning for the Gatekeeper,but disabling the voice

channels allows the Leader card to handle a signiﬁcantly higher number of

calls/hour. The IP trunk card providing DCHIP functionality can be any card

in the node including the Backup Leader (Leader 1) and Follower card.

As with the Leader card, disabling the voice channels on the DCHIP card

signiﬁcantly increases the number of calls/hour that can be processed.

The Leader card can support all Gatekeeper-routed calls, all locally-resolved

calls, or a mixture of both. The Leader card can support the same number

of Follower cards for all codecs with payloadsizes of 10, 20, and 30

milliseconds, and with VAD on or off.

Table12 "Real-time capacity of a single card node with all 24 ports enabled"

(page 108) and Table13 "Real-time capacity of an ITG-Pentium 24-port

trunk card in the Leader or DCHIP role" (page 108) show the real-time

capacity of the ITG-Pentium 24-port trunk card in the role of Leader card

and the role of DCHIP card.

Nortel Communication Server 1000

IP TrunkFundamentals

NN43001-563 02.01 Standard

Release 5.5 21December 2007