3Com 3C10402B Administrator's Manual page 232

232 C 10: SIP-M
HAPTER
O
ODE PERATIONS
SIP mode is not supported on the NBX 100. See
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for detailed system platform support information.
SIP mode on an NBX system means standard SIP support (RFC 3261)
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with no proprietary extensions to SIP. Third-party telephone features
that are dependent on non-standard SIP will not work. A SIP mode
system does not support secure SIP signaling or secure RTP. It does not
support NAT, firewalls, or RTP relay. Communication is over UDP only.
A SIP mode system uses Standard IP as the network protocol. If you
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enable SIP on a system that uses Ethernet mode or IP on the Fly, the
system automatically switches to Standard IP. You typically configure a
DHCP server to provide IP information to devices and configure Option
184 on the DHCP server to provide the Call Processor IP address.
A SIP mode system can interoperate with any other SIP endpoint,
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including gateways, devices, and SIP-enabled applications. For
example, a SIP mode system is able to interoperate with the 3Com
VCX Telephony System, a SIP-based system designed to support large
distributed enterprises.
3Com Telephones connected to a SIP mode system behave the same
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as they do when running under 3Com call control mode except for
these differences:
Conferences can include up to three parties, the conference
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originator, and two other conference parties, either internal or
external. The limit is four parties on a system that is not running in
SIP mode. However, the number of simultaneous conference
sessions supported in SIP mode increases beyond the current limit
of 12. For support for conferences that require more than 3 parties,
you can configure the optional 3Com IP Conferencing Module.
In SIP mode, the conference originator cannot forward, transfer,
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camp on, or park a conference call.
The WhisperPage feature is not available on a system running in SIP
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mode.
An external messaging application, typically the 3Com IP
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Messaging Module, provides Voice mail and Auto Attendant
menus and prompts, and Music-on-Hold. NBX Messaging is
disabled when you enable SIP.
If you do not use an external conference server, these devices can
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participate in a conference call:
3Com 3108 Wireless Telephone
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Table 50 on page 236