Cisco Systems SPA9000 manual Managing Call Forwarding, How Call Forwarding Works

Chapter 4 Configuring SPA9000 Features

Managing Call Forwarding

Managing Call Forwarding

This section describes the way the SPA9000 manages call forwarding. It includes the following topics:

•How Call Forwarding Works

•Using Call Hunt Groups, page 4-19

•Client Station Blind Transfers External Caller To DID/Hunt Group

•Using Shared Line Appearance

Note Some improvements in call forwarding have been introduced in Release 5.1 that are described in the “Bridge Mode” section on page 4-32.

How Call Forwarding Works

SPA9000 supports the call forward scenarios listed in Table 4-2.

Table 4-2 Call Forward Scenarios

Called Party	Caller	Forward Target	Remarks
Client station	Client station	Client station	Proxy only; no direct involvement
Client station	Client station	External	Very similar to calling external number
Client station	External	Client station	ACKs the 302 from called party. Then
			INVITEs the target. NOTE: If the original
			INVITE is forked to more than one client
			station, call forward is not performed.
Client station	External	External	ACKs the 302 from called party. Sends 200 to
			caller, then blind REFERs caller to target.
			NOTE: If the original INVITE is forked to
			more than one client station, call forward is
			not performed
External	Client station	External	ACKs the 302 from called party, then
			INVITEs the target

SPA9000 supports call forward by client station:

•unconditionally

•when busy

•on no answer Note the following:

•SPA9000 does not distinguish cases (1) and (2), which only makes a difference at the client station side.

•Case (3) is simply a delayed version of (1) or (2) where the 302 response from the called client station is received after a 180 response (that is, ringing has started at the called station). For cases

(1) or (2), the 302 response is typically received before any 180 response.

	Linksys SPA9000 Administrator Guide
Document Version 3.01		4-17