Step 4: Telephone and the Call Server

The call server referred to in this step differs depending on whether the telephone is H.323 or SIP. For H.323 IP telephones, the call server is the Avaya Media Server. For SIP IP telephones, the call server is the Registration Server.

In this step, the telephone and the call server exchange a series of messages, which cause the display on the telephone to prompt the user. For a new installation and for full service, the user must enter the telephone’s extension and the call server password. For a restart of an existing installation, this information is already stored on the telephone, but the user may have to confirm the information. The telephone and the call server exchange more messaging, with the expected result being that the telephone is appropriately registered.

An exception to the requirement to enter an extension and password is for H.323 IP telephones running R2.3 and later software. These telephones support a feature called Unnamed Registration. Unnamed Registration allows a telephone to register with the Avaya Media Server without an extension, assuming the Avaya Media Server also supports this feature. To invoke Unnamed Registration, take no action--just let the Extension... prompt display for 60 seconds without making an entry. The telephone will automatically attempt to register by means of Unnamed Registration. A telephone registered with Unnamed Registration has the following characteristics:

• only one call appearance,
• no administrable features,
• can make only outgoing calls, subject to call server Class of Restriction/Class of Service limitations, and
• can be converted to normal “named” registration by entering a valid extension and password.

More details about the installation process are available in the 4600 Series IP Telephone Installation Guide and in Chapter 3: Requirements of this document.