Specifications

Other IP Endpoints IP Phone Communications
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Call Manager Switch
The call manager module of the ShoreTel Voice Switches handles the Media Gateway Control Protocol
(MGCP) information from the IP phones assigned to it. After a call is connected to an endpoint, media
streams are independent of the call manager switch.
The ShoreTel Voice Switch communicates call information to other switches in the system using
ShoreTel’s enhanced SIP protocol. Every site where IP phones are in use must have a ShoreTel Voice
Switch configured to support the number of IP phones at the site.
To configure IP phone support on a ShoreTel Voice Switch, you must reserve ports for IP phone
support on the ShoreTel Voice Switch edit page in ShoreTel Director.
IP Phone Communications
IP phone communications are routed through two protocols: MGCP and RTP (Real-time Protocol).
MGCP
ShoreTel IP phones (with the exception of the 400-Series IP phones) communicate with ShoreTel
voice switches via MGCP, a device control protocol. The relationship between the switch (call
manager) and the phone (gateway) follows a master–slave model.
MGCP is used to:
 Deliver information to the IP phone display
 Set up and tear down media streams
 Report phone events such as key presses, on hook, and off hook
Real-time Protocol
Media travels through the ShoreTel system using Real-time Protocol (RTP). After call setup, media
flows directly between IP phones via RTP. The ShoreTel Voice Switch is involved only when setting up
or tearing down a call.
Boot Process
ShoreTel IP phones are pre configured by ShoreTel to work in conjunction with your network’s
Dynamic Host Configuration Protocol
(DHCP) server. After the servers are configured, when the
phones deployed are automatically added to your ShoreTel system.
After the IP phone obtains the DHCP and FTP server IP addresses, it downloads the application and
configuration files from the FTP server. The IP phone configuration file is modified by ShoreTel Director
during IP phone configuration.
If you are not using a DHCP server or it is not currently online, you can set a static IP address and
other startup parameters directly at the IP phone. Static IP addresses for IP phones can also be
assigned using the IP phone setup menus.