TD 92685EN
28 June 2012 / Ver. A
Troubleshooting Guide
Ascom i62 VoWiFi Handset
26
3. The VoWiFi Handset as
3.8.3 Redirect Servers
A redirect server generates 3xx respo
nses to requests it receives, directing the client to retry
the request using one or more alternative Uniform Resource Identifiers (URIs), which are
presented in the 3xx response. 3xx is a SIP response class used to indicate that further
action needs to be taken in order to complete a the request.
In the following example, user1 places a call to user2 using a redirect server because user2
has temporaril
y moved to serverc. User2’s address has temporarily become
sip:user2@serverc.com. The INVITE message is first sent to the redirect server, which returns
a 302 MOVED TEMPORARILY response containing a contact header with user2’s current SIP
address. User1 then generates a new INVITE message and sends it to user2 via the proxy
serverC:
Figure 11. Call Redirect
Note: A user attempting to call a
recipient that has moved permanently to a new position
will receive a 301 MOVED PERMANENT message after the initial INVITE.
3.8.4 Call Completion
When one of the parties terminates the call, a final exchange of SIP
m
essages occurs. The
party that initiates the termination sends a BYE message directly from one handset to the
other party, and the other party handset returns an 200 OK and that is the completion of
the call. For example:
Figure 12. Call Completion
Note: If the WLAN is using a controller based solution the SIP message flows in all of the
above illustrations should include the controller because all WLAN traffic is bridged between
wireless and wired network segments by the controller and not the APs. That means that
traffic goes back and forth on the LAN cable to the controller. Depending on the
configuration and functionality of the SIP proxy, the Real-time Transport Protocol (RTP)
To Next Page
Loading...
Need help?
General
