Voice and IP communication: Support for SIP protocol in Cisco Unified Communication (1)

The SIP Protocol provides a standard-based IP communication method for multiple devices and applications. This White Paper describes the support for the SIP protocol in the Cisco communications system. Cisco's Unified Communication System includes IP voice, data and video communication products and applications, which can help organizations communicate more effectively, simplify business processes, and achieve higher incomes.

Cisco Systems®Provides SIP technology through a comprehensive development plan, including support for sip rfc on a variety of Cisco products. The Cisco plan also integrates enhanced features of the sip rfc and Cisco Unified Communication System. Organizations that use SIP-compliant Cisco products can now make their communications more scalable and modular. Since the SIP technology will be extended to more communication types, devices and applications in the future, these organizations will also build a solid platform for the unique and advanced features brought about by the application of the SIP technology.

Why should we consider using SIP?
Every year, multiple new devices will be released for technological innovation to provide new methods and addresses for people's connections. In many cases, it is discovered that the convenience of these new devices is greatly reduced by the complexity of managing various addresses, messages and tools with different features, or even overlapping tools. The use of new devices also raises the question of how to contact others in the best way: "should I send an email or send a voice message? Which number should I use for voice messages? Is his office phone number or mobile phone number ?" Sharing Communication Information between devices may be cumbersome, but a network with a well-designed generic signaling protocol can greatly reduce its complexity.

By using the SIP technology, enterprises can solve the above problems and obtain a powerful and flexible platform that can create new communication applications. In a SIP environment, all devices run as part of a system-you can contact the user with a few addresses, you can also easily transfer communication from one device to another.

As defined by ietf rfc, SIP is a peering multimedia signaling protocol that can be integrated with other Internet services to provide a wide range of communication channels. SIP supports communication between IP phones, desktops and laptops, personal digital assistant PDAs, and mobile phones that comply with standards. SIP-based systems provide innovative services, including Web-based communication, user mobility, network status and preferences, and multi-party collaboration.

The advantage of SIP is an indispensable part of IP communication systems and smart networks. In enterprises or organizations, SIP can combine a variety of different applications, devices, and communication processes to provide powerful new features and features.

Implementing the SIP technology in an IP converged network has many advantages, including using customizable new applications to increase network value and user productivity, and getting rid of vendor dependencies, there is more room to choose applications and terminals, and it can reduce device costs and manage communication service expenses. Cisco undertakes to support the implementation of SIP-based standard communication devices to provide customers with maximum investment protection, interoperability and more deployment options.

Cisco SIP Technical Support
Cisco Systems has a special advantage in taking advantage of all the features of SIP. Cisco employees have played an important role in the formulation of SIP standards and have been at the forefront of the development of SIP technology. In addition, Cisco employees write or co-write more SIP-related drafts and RFC than any other company. To learn more about the background information of SIP and Cisco's participation in developing SIP standards, see the White Paper: SIP: The next step in implementing integrated IP communication.

With the largest SIP product line in the industry, Cisco is applying its SIP experience to enterprise solutions. Cisco is also working with other companies to ensure that their SIP applications can be seamlessly integrated with Cisco infrastructure.

Customers can be confident that Cisco has a mature strategy that integrates SIP technology to protect their investment in networking and communication systems, so that they can safely port to SIP.

This article describes the SIP feature and the support of Cisco Unified Communication System products.

Call Processing System
The call processing system extends the features and functions of Enterprise telephones to IP phones, media processing devices, voice gateways, multimedia applications, and other devices. A call processing system integrates multiple distributed system diagrams for unified messaging, video, and multimedia conferencing. 1 ). Cisco's Unified Communication call processing system, gateway, session boundary controller, and IP phone all support the sip ietf rfc 3261 standard.

Figure 1. Cisco SIP support in Enterprise call handling solutions

Table 1 feature table
Local Gateway	Cisco uniied CallManager and Cisco uniied CallManager Express	SIP voice message
Meeting	Soft telephone SIP Soft Client SIP telephone SIP Conference SIP gateway SIP Application
	CTI application IP Phone

Cisco uniied CallManager
Cisco uniied CallManager 5.0 provides a call processing solution with a built-in SIP function that supports call control and registration of SIP terminals. Cisco uniied CallManager 5.0 provides local SIP protocol support for direct connections between the SIP terminal and the SIP network without the need to add devices or software. Cisco's practice of integrating SIP into the ip pbx system is unique, which protects customer investment and supports a wide range of feature sets for SIP terminals, and enables the customer to port to the SIP application and terminal according to their own progress.

Enterprises that have deployed Cisco uniied CallManager can use Cisco uniied IP Phones using the SCCP protocol developed by SIP or Cisco. These protocols can coexist in the Cisco Unified CallManager environment and can be gradually transplanted to the SIP while protecting the investment of existing devices. In addition to supporting SIP on Multiple Cisco uniied IP Phone models, Cisco uniied CallManager also provides registration and feature support for all terminals that comply with RFC 3261.

Cisco deploys SIP based on RFC to implement core telephone features. To provide many SCCP-based features, Cisco also supports other SIP features, part of which are from the upcoming RFC. The system can also use the Cisco Unified Presence Server to detect and transmit the user's network status information.

The customer will benefit from the consistency of the call characteristics on the SIP and SCCP phones. For example, a SIP or SCCP phone can have the same extension number. In addition, the call can be retained from a SIP Phone, and then picked up from a SCCP phone-and vice versa.

SIP running on Cisco uniied IP Phones 7905G, 7911G, 7912G, 7940G, 7941G, 7941G-GE, 7960G, 7961G, 7961G-GE, 7970G, and 7971G-GE can help customers obtain system-level SIP features, for example, network status and interoperability with third-party SIP services. In addition, the SIP terminal helps Cisco uniied CallManager 5.0 configure, register, and manage special SIP calls and third-party SIP calls.

The SIP relay interface on Cisco uniied CallManager 5.0 complies with RFC 3261 and supports many other sip rfc. It can integrate a series of voice and video call applications on the SIP Trunk Line. When it comes with Cisco Unity®When the uniied Messaging system is used together with the Cisco Unified MeetingPlace Messaging multimedia conferencing system, the interoperability on the Cisco Unified CallManager SIP relay interface can improve the Conference and application support. Through the use of SIP relay and SIP network interfaces, telecom operators can provide new services that support SIP and network status for their enterprise customers.

Because Cisco Unified CallManager has built-in SIP support, customers can obtain a package of solutions to provide enterprise-level features and functions, enhance interoperability, and support SIP application innovation. Currently, Cisco clients with corresponding valid service contracts can upgrade Cisco Unified CallManager 5.0 to the SIP function for free.

For more information, visit www.cisco.com/go/voice.