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Cisco VISM Installation and Configuration Guide
Release 3.0, Part Number OL-2521-01 Rev. D0, June 2004
Chapter1 Overview of the VISM and VISM-PR Cards
VISM and VISM-PR Card Features
•Voice over ATM (VoATM) using AAL2 cells—No Logical Link Control/Subnetwork Access
Protocol (LLC/SNAP) encapsulation.
Note Multiplexing is not supported for AAL2 SVCs.
•VoIP using AAL5 cells to RFC 1889.
•Extended Superframe (ESF) framing with or without cyclic redundancy check (CRC).
•Pulse code modulation (PCM) A/Mu law codecs.
•Programmable 24, 32, 48, 64, 80, 96, 112, 128 ms tail d ela y n ear end EC AN.
•Voice compression with the following standards:
–
G.711
–
G.726-16k
–
G.726-24k
–
G.726-32k
–
G.726-40k
–
G.729a
–
G.729ab
–
G.723.1-H
–
G.723.1a-H
–
G.723.1-L
–
G.723.1a-L
Note The G.723.1 codecs are not supported in combination with the VISM card . The G.723.1
codecs are supported with the VISM-PR card.
•Nx64 clear channel (N = 1 only) support.
•Voice activity detection (VAD) and comfort noise generation (CNG) using variable threshold energy
(Cisco proprietary).
•Call agent Simple Gateway Control Protocol (SGCP) Version 1.0, 1.1, 1.5, SGCP 1.1+, 1.5, and
Media Gateway Control Protocol (MGCP) 0.1 and 1.0.
•Backhauling channel associated signaling (CAS) signaling to a call agent using xGCP (backhauling
can be accomplished with any supported SGCP and MGCP protocol).
•Backhauling Primary Rate Interface (PRI) signaling via Reliable User Da tagr am Pro t oco l (RUDP)
to a call agent.
•Common channel signaling (CCS) transport across an AAL5 trunk.
•Fax and modem VoIP bearer transmissions.
•Dual (redundant) virtual circuits across the packet network.
•Full continuity testing (COT). Supports origination and terminating loopback and transponder COT
between VISM and the central office on the TDM side.
•Loop timing, which can be used as the master clock f or t he e nti re M G X 80 00 Ser ies pla tfor m an d
local clock.