SERVICES AND TOPOLOGIES CALL SERVER : VOICE ON IP
Ed. 042/12 Réf. 3EH 21000 BSAA
The Alcatel OmniPCX Office VoIP offer does not provide:
- specific services such as optimization of call transfers or forwarding such as exist with the ISVPN;
likewise, H.450 protocol is not supported.
- the FoIP (Fax over IP) service. A Fax (or Data) call must not be routed via Voice over IP; fax trans-
mission is not guaranteed.
- the encrypting of VoIP channels.
Quality of Service (QoS)
Mechanisms in the system's ARS determine whether a VoIP call to a remote H.323 gateway can be
made without degradation of the bandwidth (see "Installation - Configuration" File).
The aim of quality of service in the network sense is to provide "end-to-end" QoS for all the audio IP
packets.
To achieve this, the system supports the IP ToS (IP Type of Service): each IP VoIP packet contains a 3-
bit precedence field indicating a level of priority. This information can be used by the network equip-
ment (routers, gateways, etc.) to assign a level of priority to the IP voice packets with respect to the IP
data packets. Alcatel OmniPCX Office also supports "DiffServ" (RFC 2475).
Nota : End-to-end quality of service can only be guaranteed if all the items of equipment in the
network are IP ToS or DiffServ compatible.
Principle of operation of the CoCPU board
The CoCPU board fulfils the following functions:
Environment
The H.323 gateway (VoIP CoCPU board) connects either to a 10 Mbps Ethernet LAN or to a 100 Mbps
Fast Ethernet LAN via an RJ45 cable, while the IP Enablers provide a 10 Mbps Ethernet connection (IP
Enabler V1) or a 10/100 Mbps Ethernet connection (Enabler V1S) and integrate a 2-port Hub (V1) or
switch (V1S) permitting chaining with a PC.
(Masterboard) TFTP Server / DHCP Server
H.323 Gateway / Gatekeeper
Ë
Soft stack
T C P / U D P / I P
Boot/BIOS Operating System Kernel / R T
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