会谈边界控制器
会谈边界控制器（Session Border Controller, SBC），一种NAT穿透的方式。SBC可确保VoIP 安全，又可提供媒体代理服务器的套件。
SBC架构于IMS网络之上，可作为IMS网络的SIP和RTSP的 Proxy Server，所有的SIP与RTSP讯息都会透过SBC来处理，SBC更具备NAT穿透的功能。目前思科与 Kagoor 对会谈边界控制技术有突破性的发展。
功能
SBCs 会维持整个会议状态并提供以下功能:
- 网络安全 – 保护网络以及其他装置:
- 连结 – 允许不同网域之间的沟通:
- 服务质量 – QoS 的政策是网络状态的优先取舍问题. 其功能如下:
- Traffic policing
- Resource allocation
- Rate limiting
- Call admission control
- TOS/DSCP bit setting
- Regulatory – many times the SBC is expected to provide support for regulatory requirements such as:
- emergency calls prioritization and
- lawful interception
- Media services – many of the new generation of SBCs also provide built-in digital signal processors (DSPs) to enable them to offer border-based media control and services such as:
- DTMF 中继与互连
- 媒体转码
- Tones 与 announcements
- 数据与内网传真
- 支援音讯与影讯
- 统计与传单资讯 – since all sessions that pass through the edge of the network pass through the SBC, it is a natural point to gather statistics and usage based information on these sessions.
参考书目
- Hautakorpi, J.; Camarillo, G.; Penfield, R.; Hawrylyshen, A.; Bhatia, M.. Requirements from SIP (Session Initiation Protocol) Session Border Control Deployments. IETF. April 2010. RFC 5853.
- Sinnreich, Henry; Johnston, Alan B., Internet Communication Using SIP, Wiley: 180, 2001, ISBN 0-471-77657-2
- Juniper Networks, The Benefits of Router-Integrated Session Border Control (PDF), 2009, （原始内容 (PDF)存档于2012-11-07）
- Sonus Networks WhitePaper — Performance reality of Session Border Controllers
- Acme Packet White Paper （页面存档备份，存于互联网档案馆） — defines the need for session border controllers for interactive IP services
- AudioCodes White Paper — on Enterprise Session Border Controllers.