Mitel Inter-Tel 5000 Installation And Maintenance Manual page 301

NOTICE
Positive Disconnect. Signaling a call termination from the CO over an analog loop start line
differs from CO to CO. Because the SIP/MGCP gateways detect this call event differently,
you must pay particular attention to how the CO and the SIP/MGCP gateway detect far-end
call termination. If the SIP/MGCP gateway you are installing relies on the CO to detect dial
tone to signal a call termination, then a user could possibly hookflash and place a second call
before the system realizes that a new call is being made. If this occurs, the appropriate toll
restrictions are not applied to the new call. If the CO detects dial tone to indicate a terminated
call, Inter-Tel recommends that the CO line used with the SIP/MGCP gateway be restricted to
local calls.
Also, if the CO caller hangs up before the user, the user may still be connected to the CO
until the user either hangs up or the SIP/MGCP gateway detects dial tone. The user may
eventually hear reorder tone or a message that says, "If you would like to make a call..." until
they hang up.
SIP Gateway
The system supports SIP (Session Initiated Protocol) trunks to reach the CO. SIP trunks allow
the system to communicate with the CO via SIP-enabled gateways. As the SIP protocol
becomes more and more popular, it is important to be able to communicate to SIP gateways in
the IP-centric world.
The following new SIP gateways are available through the Inter-Tel
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These gateways replace the AudioCodes MP-104 SIP/MGCP Gateway that has gone end-of-
life in October 2006. Both gateways support analog Foreign eXchange Office (FXO) ports. The
setup procedure is different for each device; the MP-114 gateway uses a Web interface called
the AudioCodes Web administrator, while the AFT 400 gateway uses a Configuration Manager
program and a Command Line Interface (CLI). Existing systems must upgrade to v2.4 or later to
support the gateways. For more information, refer to the Inter-Tel Axxess/5000 Quintum SIP
Gateway Installation Manual (document part no. 835.3123) or the Inter-Tel Axxess/5000
AudioCodes MP-114 SIP Gateway Installation Manual (document part no. 835.3202).
SIP trunks support the following functionality:
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®
Inter-Tel 5000 Installation Manual – Issue 2.4, May 2008
®
Quintum AFT 400 SIP gateway
™
AudioCodes MP-114 SIP gateway
They are transparent to the system user because SIP trunks act like any other CO trunk in
the system.
They support transferring trunks, putting trunks on hold, and connecting trunks to
conferences similar to other CO trunks in the system.
They support making and receiving calls by any endpoint.
They support peer-to-peer audio by IP endpoints.
They reside in CO trunk groups like other trunks so that SIP trunk calls can be routed
using Automatic Route Selection (ARS).
They support Emergency Number calls, such as 911 in the United States or 999 in Europe,
the same as SIP/MGCP trunks.
Chapter 5: Installation
SIP Gateway
® ®
CommSource division:
Page 5-179