Cisco SPA303 - Chapter 4: Configuring SIP, SPCP, and NAT; Session Initiation Protocol and Cisco IP Phones

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Cisco Small Business SPA300 Series, SPA500 Series, and WIP310 IP Phone Administration Guide 98
Configuring SIP, SPCP, and NAT
The Cisco SPA IP Phones use the following protocols:
• Session Initiation Protocol (SIP)—Cisco SPA300 Series, Cisco SPA500
Series, WIP310
• Cisco Smart Phone Control Protocol (SPCP)—Cisco SPA300 Series, Cisco
SPA500 Series
This chapter describes how to configure the phone protocols and other
parameters. It contains the following sections:
• Session Initiation Protocol and Cisco IP Phones, page 98
• Configuring SIP, page 101
• Configuring SPCP on the Cisco SPA525G/525G2, page 122
• Configuring SPCP on the Cisco SPA300 Series and Cisco SPA50XG,
page 123
• Network Address Translation (NAT) and Cisco IP Phones, page 123
Session Initiation Protocol and Cisco IP Phones
Cisco IP phones use Session Initiation Protocol (SIP), allowing interoperation with
all ITSPs supporting SIP.
SIP handles signaling and session management within a packet telephony
network.
Signaling allows call information to be carried across network
boundaries.
Session management controls the attributes of an end-to-end call.
The following diagram shows a SIP request for connection to another subscriber
in the network.