Cisco SIP Proxy Server Data Sheet
PRODUCT OVERVIEW
The Cisco® SIP Proxy Server is a software application that provides call-routing services in an IP telephony network. Using the Cisco SIP Proxy Server, service providers and enterprises can create large-scale, highly reliable packet voice networks.
Session Initiation Protocol (SIP) is an Internet Engineering Task Force (IETF) multimedia communications standard. The Cisco SIP Proxy Server combines the standard functions of a SIP proxy server and a SIP registrar with additional features to create an IP telephony infrastructure component.
The Cisco SIP Proxy Server is part of the Cisco Voice Infrastructure and Applications (VIA) solution for service providers. Service providers can use the Cisco SIP Proxy Server to offer voice services between SIP-based application service providers (ASPs) and the public switched telephone network (PSTN). The Cisco SIP Proxy Server also provides residential voice services over broadband access as part of the Cisco Broadband Local Integrated Services Solution (BLISS). Enterprises can use the Cisco SIP Proxy Server for internal IP telephony transit among enterprise voice gateways and SIP-capable IP PBXs, as well as interconnection with the PSTN. Examples of Cisco SIP Proxy Server deployments are depicted in Figure 1.

Product Operation
The Cisco SIP Proxy Server accepts registration requests from SIP endpoints such as IP telephones, residential voice gateways, and PC applications, creating a dynamic record of the endpoint's current contact address. Static registrations can also be configured directly on the Cisco SIP Proxy Server. When the Cisco SIP Proxy Server receives a SIP "Invite" (call setup) request, it searches its registry to locate the desired endpoint. If no match is found in its registry, the Cisco SIP Proxy Server can use external Telephone Number Mapping (ENUM) or location request (LRQ) queries, or locally configured static routes to determine where to forward the request.
The Cisco SIP Proxy Server can perform a digest authentication of SIP Register and Invite requests, and can encrypt SIP requests and responses using Transport Layer Security (TLS). The Cisco SIP Proxy Server can generate RADIUS accounting records for all call attempts.
Redundant deployment of the Cisco SIP Proxy Server can provide high availability and increased performance. Both servers in a pair are active, sharing dynamic registration data. An external means, such as Domain Name System (DNS) services (SRV) records, must be used to distribute SIP requests between servers in a redundant deployment.
A Graphical User Interface (GUI) is provided to configure the Cisco SIP Proxy Server. Configuration data is stored in a local database, which is automatically replicated in redundant deployments. A Simple Network Management Protocol (SNMP) interface is also provided to monitor and control the Cisco SIP Proxy Server.
Product Specifications
Table 1 lists the product functions, Table 2 provides platform information, and Table 3 provides ordering information about the Cisco SIP Proxy Server.
Table 1 Cisco SIP Proxy Server Product Functions
Recommended Platforms and Performance
Recommended Platforms
IBM x336: http://www-03.ibm.com/servers/eserver/xseries/x336.html
Sun Fire V120: http://www.sun.com/servers/entry/v120/index.html
Sun Netra 240: http://www.sun.com/products-n-solutions/hw/networking/240/
Platform Characteristics and Performance
Table 2 Cisco SIP Proxy Server Platform Information
Notes About Performance
Up to 1000 TCP connections can be made per server.
IBM servers can sustain peak rps and cps concurrently.
For Sun servers with concurrent registrations and calls, a conservative engineering guideline is:
X + Y <= 80 percent, where
X = (expected peak rps / value in table) * 100 percent
Y = (expected peak cps / value in table) * 100 percent
Performance assumptions include:
30 percent overhead allowed for other featuresDisk mirroring not used
Availability and Ordering Information
Table 3 Cisco SIP Proxy Server Ordering Information