SIP Server Introduction

The SIP server is used to provide services such as voice and video to users in the SIP network. The main functional entities in the SIP network include: SIP server, user terminal, AAA server, network management server, application server, domain name server, and media server. The network operator can select a suitable functional entity to provide services such as voice and video to the user according to actual operational needs.

The SIP network can communicate with the DN/PLMN network, H.323 network or softswitch network through the Interworking Unit (IWF). The IWF is a logical functional entity, and its functions can be embedded in the SIP server, or can be implemented by a softswitch device or other functional entities such as a SIP gateway. When the IWF is not embedded in the SIP server, the interface protocol between the SIP server and the IWF is the SIP protocol. Interworking between SIP networks of different operators can be achieved through IWF. The technical requirements of the SIP server device do not stipulate the specific implementation of the IWF.

The SIP server adopts the IP bearer mode and provides functions such as call control and processing functions, service provision/support functions, user management functions, protocol processing functions, route processing, access authentication, and accounting information collection. Operation and maintenance /network management functions, interworking functions, security functions (optional), black and white list function, congestion control function (optional).