SIP Architecture

To see how to generate thousands of SIP calls and stress test a SIP network  
UAC (user agent client) Caller application that initiates and sends SIP requests.
UAS (user agent server) Receives and responds to SIP requests on behalf of clients; accepts, redirects or refuses calls.
SIP Terminal Supports real-time, 2-way communication with another SIP entity. Supports both signalling and media, similar to H.323 terminal. Contains UAC.
Proxy Contacts one or more clients or next-hop servers and passes the call requests further. Contains UAC and UAS.
Redirect Server Accepts SIP requests, maps the address into zero or more new addresses and returns those addresses to the client. Does not initiate SIP requests or accept calls.
Location Server Provides information about a caller’s possible locations to redirect and proxy servers. May be co-located with a SIP server.
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Additional Information