Specifications

Engineering Guidelines
30
When determining network bandwidth, consider voice mail sessions as being active 100% of
the time. The number of voice mail sessions determines the bandwidth required. With G.711
voice streams and 30 active sessions, a minimum of 4.0 Mbps must be provided:
(30 x 96.8 kbps + 10% (signalling)) / 80% = 4.0 Mbps
Where the unit is used as a dedicated voice mail server, consider the number of other functions
provided on the box. As more voice mail sessions are activated the number of IP phones that
can be handled decreases. Typically 30 VM sessions and 700 users are in direct opposition.
Consider multiple units beyond approximately 400 users and 20 voice mail sessions.
Configuration Tables
The following tables show the maximum capacity for each feature or resource in each type of
controller. You cannot configure a system to support all maximum values at the same time.
• IP devices includes all telephones and all applications which emulate telephones, including
SIP phones.
• TDM devices includes all ONS/OPS and DNIC sets but not analog or digital trunks.
• Compression channels includes only those channels that are necessary within the ICP to
connect TDM ports to IP trunks. Most IP sets can stream compressed audio to another IP
port without using any ICP resources. Those that can’t, simply stream uncompressed audio
(the call is not routed using internal ICP resources).
• Digital links refers to embedded BRI (4 links, 8 lines or trunks per module), embedded
T1/E1 (1 link, 23/24/30 trunks, or 2 links, 46/48/60 trunks per module), or external T1/E1
(2 links, 46/49/60 trunks per NSU cabinet). It does not include the external BRI NSU, which
is an adapter that can be added behind any E1 link at up to 15 trunks per cabinet.