Specifications

System Hardware
INTER-TEL
®
CS-5200/5400 ADMINISTRATOR GUIDE, ISSUE 1.0 – April 2005
Gateways
Page 67
Gateways
AudioCodes MP-104 MGCP Gateway
The system also supports IP-based solutions for providing local Public Switched Telephone
Network (PSTN) connectivity using a third-party Media Gateway Control Protocol (MGCP)
device. For information about currently supported MGCP devices, contact your local autho-
rized Inter-Tel dealer..
AudioCodes MP-104 SIP Gateway
The system supports SIP (Session Initiated Protocol) trunks to reach the CO. SIP trunks allow
the system to communicate with the CO through 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. Inter-Tel currently supports the AudioCodes MP-104 SIP gateway (with
software version 4.2).
Inter-Tel does not provide technical support for any SIP gateway other than the AudioCodes
MP-104 SIP gateway. SIP trunks support the following functionality:
• 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 con-
ferences similar to other CO trunks in the system.
• They support making and receiving calls by any endpoint.
• They support peer-to-peer (P2P) 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 911 (999 in Europe) calls the same as MGCP trunks.
The MP-104 does not support the following features:
• Pause digits. These digits are used to program a speed-dial or other digit string.
• SIP registration which is used for authentication purposes.
CAUTION
If an IP or SIP device user dials 911 from a remote location and an MGCP gateway is not
present and configured properly, the call will be placed from where the system is located
rather than from where the user is located. Because 911 services use Caller ID to help locate
the caller, emergency service could be misdirected or delayed. Also, the 911 service
contacted may be local to the system, but not to the IP or SIP device. All IP and SIP device
users should be alerted to this situation and instructed to use a local telephone line for
placing emergency calls if an MGCP gateway is not present and/or functioning properly. Also
note that IP and SIP devices will not function in the event of a power failure at either the local
site or the system location. Inter-Tel will not be held responsible for any problems resulting
from an unavailable line that is connected to the MGCP gateway. Inter-Tel also recommends
that users regularly test the MGCP gateway for dial tone.