Software requirements 47
Capacity Each CS 1000 main office can support up to 255 branch offices. Each
Branch Office supports up to 400 IP Phone users. However, since all IP
Phones register with the main office, the governing factor is the maximum
number of IP Phones that can be supported at the main office. This
means the total number of IP Phones in all offices can be no greater
than the capacity of the main office, as determined using Communication
Server 1000E Planning and Engineering (NN43041-220),Communication
Server 1000M and Meridian 1 Large System Planning and Engineering
(NN43021-220),orCommunication Server 1000M and Meridian 1 Small
System Planning and Engineering (NN43011-220).
The configuration of an MG 1000B platform depends on:
•the number of line and trunk cards being provisioned
•the number of Media Cards required to providea sufficient number of
DSP channels

Media Card DSP capacity

The number of DSP ports to provision depends on the trunk-to-telephone
ratio. A rule-of-thumb is to have the number of ports greater than or
equal to the number of trunks configured. See Communication Server
1000S: Planning and Engineering (NN43031-220) (or Communication
Server 1000M and Meridian 1 Small System Planning and Engineering
(NN43011-220) for converted Small Systems) formore information.
If digital telephones and analog (500/2500-type) telephones are equipped at
the Branch Office, additional DSP ports are needed for digital-to-IP Phone
and analog-to-IP Phone connections. The number of additional DSP ports
must be equal to or greater than the expected number of simultaneous
connections of these types. The user can engineer fewer DSP ports
depending on their desired blocking ratio.
Software requirements
This section describes the relative software versions required in the
main office and Branch Office locations. The actual software packaging
requirements are given in "Main office requirements" (page 192) and
"Branch Office requirements" (page 193).

Main and Branch Office running the same release

Normally, the main office and associated Branch Office run the same
software release.
However,a Branch Office location can be running an ear lier software
release than that running at the main office. This situation is discussed in
the next section.
Nortel Communication Server 1000
Branch Office Installation and Commissioning
NN43001-314 01.02 Standard
Release 5.0 20 June2007
Copyright© 2007, Nor tel Networks
.