Chapter 1: Vcx V7122 Sip Overview - 3Com VCX V7122 User Manual

C 1: VCX V7122 SIP O
HAPTER VERVIEW
The VCX V7122 SIP (Session Initialization Protocol) Voice over IP VoIP) gateway enables
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voice, fax, and data traffic to be sent over the same IP network. The VCX V7122 gateway
provides excellent voice quality and optimized packet voice streaming over IP networks.
The VCX V7122 uses the award-winning, field-proven DSP voice compression technology
TM
used in other TrunkPack series products.
The VCX V7122 incorporates 1, 2, 4, 8 or 16 E1 or T1 spans for connection, directly to
Public Switched Telephone Network (PSTN) / Private Branch Exchange (PBX) telephony
trunks, and includes one or two 10/100 Base-TX Ethernet ports for connection to the
network.
The VCX V7122 supports up to 480 simultaneous VoIP or Fax over IP (FoIP) calls,
supporting various Integrated Services Digital Network (ISDN) Primary Rate Interface (PRI)
protocols such as EuroISDN, North American NI2, Lucent 5ESS, Nortel DMS100 and others.
In addition, it supports different variants of Channel Associated Signaling (CAS) protocols for
E1 and T1 spans, including MFC R2, E&M immediate start, E&M delay dial/start, loop start
and ground start.
The VCX V7122 gateway, best suited for large and medium-sized VoIP applications, is a
compact device, comprising a 19-inch 1U chassis with optional dual AC or single DC power
supplies.
The deployment architecture can include several VCX V7122 gateways in branch or
departmental offices, connected to local PBXs. Call routing is performed by the gateways
themselves or by SIP Proxy(s).
The VCX V7122 gateway enables users to make low cost long distance or international
telephone/fax calls between distributed company offices, using their existing telephones/fax.
These calls are routed over the existing network ensuring that voice traffic uses minimum
bandwidth.
The VCX V7122 can also route calls over the network using SIP signaling protocol, enabling
the deployment of "Voice over Packet" solutions in environments where access is enabled to
PSTN subscribers by using a trunking media gateway. This provides the ability to transmit
voice and telephony signals between a packet network and a TDM network. Routing of the
calls from the PSTN to a SIP service node (e.g., Call Center) is performed by the VCX
V7122 internal routing feature or by a SIP Proxy.
Figure 1 below illustrates typical VCX V7122 gateway applications over VoIP Network.
3Com VCX V7122 SIP VoIP Gateway User Manual 13