Cisco Systems SPA9000 manual How Voicemail Works, Invite sipmailbox-manage-url SIP/2.0

Chapter 3 Configuring Voice Service and Voicemail

Managing Voicemail

There are three groups of voicemail operations:

•Depositing voicemail

•Managing voicemail from a client station or from an external number

•Subscription to voicemail notification and receiving voicemail notification

SPA9000 assumes that a voicemail account can include more than one mailbox ID (MBID). The voicemail account is defined with a user-ID, which can be the same as the line interface user-ID.

Three parameters must be configured on the SPA9000 for each line to support these operations: <Mailbox Deposit URL>, <Mailbox Manager URL>, and <Mailbox Subscribe URL>.

Note The mailbox ID should be set to the extension number.

Voicemail service may be offered by a service provider different from the ITSP. For example, you can configure Line 1, 2, and 3 with accounts on an ITSP, but configure Line 4 an account with a different Internet voicemail service provider (IVMSP). The SPA9000 can be configured to bridge calls between the ITSP and the IVMSP when necessary (when depositing or checking voicemail by an external caller) using the <VMSP Bridge> parameter on each line interface.

How Voicemail Works

When a user checks voicemail from a client station, the SPA9000 sends an INVITE on its behalf to the configured <Mailbox Manage URL>. For example:

INVITE sip:mailbox-manage-url SIP/2.0

Via: SIP/2.0/UDP 192.168.2.205:5060;branch=z9hG4bK-171eb6b5

From: <sip:37683102@sip.myitsp.com>;tag=300704dd2590d20bo2;ref=5031;mbid=53371

To: <sip:mailbox-manage-url>

Call-ID: 58a2b2c5-66e2bd43@192.168.2.205

CSeq: 101 INVITE

Max-Forwards: 70

Contact: <sip:37683102@192.168.2.205:5060> Ö

Here the client station is at extension 5031 and the mailbox ID is 53371. The voicemail server should then prompt the caller to enter a PIN and access the voicemail features for the given mailbox.

A user should also be able to call an external number explicitly from anywhere to retrieve voicemails. When the voicemail server receives such a call, it should prompt the caller to enter the mailbox ID and then the PIN number. If the user-ID of the voicemail account cannot be uniquely identified from the mailbox ID or from the called number, the server must first prompt the user to enter the user-ID before proceeding.

Note If an EXT-To-DID mapping exists for the calling extension on the line interface, the user-ID and display name fields of the FROM header are replaced by the mapped DID number and the display name assigned to the phone, respectively. In this case, a DIVERSION header similar to the REFERRED-BY header is also included.

	Linksys SPA9000 Administrator Guide
Document Version 3.01		3-21