Nortel 1000 Description, Installation And Operation Manual page 146

Page 146 of 644
553-3001-363 Standard 2.00
ITG engineering guidelines
Media Card 32-port trunk card Leader 0 and DCHIP card real-time
capacity
The Media Card 32-port trunk card is based on the Intel StrongARM CPU.
The real-time capacity analysis of the Media Card 32-port Leader 0 card is as
follows. The following assumptions are made:
1 The minimum number of Follower cards required is a function of the call
rate (which is limited by the Leader and DCHIP card) and the Average
Hold Time (AHT) (which is a function of the number of channels per
card). The number of Follower cards is calculated by the number of voice
channels required (using Poisson 1 percent blocking Grade of Service)
divided by the number of channels per card. The number of Follower
cards required is affected by whether the Leader card has the voice
channels enabled or not.
2 Peakedness factor for call processing is equal to 1.3. This implies that
30% fluctuation is allowed in voice traffic.
3 Calls can terminate or originate on the Leader card. Voice ports are
allowed on the Leader card, depending on configuration for anticipated
traffic. Enabling the voice ports on a Leader or DCHIP card decreases the
number of Follower cards required by one card, but can substantially
affect the amount of traffic that can be handled for that node.
4 When VAD has been enabled in OTM 2.1 (and later), the voice
fluctuation factor is equal to 1.5. A voice fluctuation factor of 1.5 implies
that, during a conversation, voice is on 50% more than the average, in
contrast to silence periods of a conversation. With VAD status equal to
"off", the voice fluctuation factor is equal to 1.1.
5 15% of CPU real-time has been reserved for Network Monitoring
Module.
September 2004