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Cisco BTS 10200 Softswitch SIP Feature and Provisioning Guide, Release 5.0
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Chapter2 SIP Subscribers
SIP Subscriber Calls
Figure 2-2 shows how an incoming request is processed, and indicates the role of the Authentication
Service in the BTS 10200.
Figure 2-2 Authentication and Processing of an Incoming Request (for Example, INVITE)
The BTS 10200 validates the hostname of the ReqUri of every incoming SIP request against the list of
names provisioned in the Serving-Domain-Name table. The BTS 10200 hostname used by devices (in
the ReqUri), when they send requests to the BTS 10200, should be provisioned in the
Serving-Domain-Name table of that BTS 10200. If a name is not provisioned (and therefore not found)
in the Serving-Domain-Name table, the BTS 10200 rejects the SIP request with a “404 Not Found
ReqUri Serving Domain” response.
The BTS 10200 authenticates IP phones by using the MD5 digest defined in RFCs 3261 and 2617. The
BTS 10200 verifies a user’s credentials on each SIP request from the user. For more information, see the
User Authorization table in the Cisco BTS 10200 Softswitch CLI Database.
SIP Subscriber Calls
SIP subscribers must present valid credentials on a SIP INVITE message in order to place calls.
The system allows SIP subscribers to call other SIP subscribers or SIP trunks connected to the
BTS 10200. The provisioned dial plan determines whom a subscriber can call. A SIP subscriber can
receive a call as long as the subscription’s registration is current, or a static registration has been
provisioned.
87898
Invite
Cisco BTS 10200
Softswitch
SIP Phone 1
Invite
SIP Phone 2
401
ACK
Invite
ACK
200
BYE
200
BYE
401
BYE
ACK
200
200
IP IP