Cisco SPA 525G2

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Cisco Small Business SPA 300 Series, SPA 500 Series, and WIP310 IP Phone Administration Guide 87
Configuring SIP, SPCP, and NAT
The Cisco SPA IP Phones use the following protocols:
• Session Initiation Protocol (SIP)—Cisco SPA 300 Series, Cisco SPA 500
Series, WIP310
• Cisco Smart Phone Control Protocol (SPCP)—Cisco SPA 300 Series, Cisco
SPA 500 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 87
• Configuring SIP, page 90
• Configuring SPCP on the Cisco SPA 525G/525G2, page 110
• Configuring SPCP on the Cisco SPA 300 Series and Cisco SPA 50XG,
page 111
• Network Address Translation (NAT) and Cisco IP Phones, page 111
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.