共查询到17条相似文献,搜索用时 93 毫秒
1.
分析了IMS中媒体层、控制层和应用层的认证机制,针对IMS用户漫游时跨域认证造成开销过大的问题,在IMS控制层提出了一种跨域信任机制。该机制通过在HSS和S-CSCF中增加信任证书数据库、证书目录、声明发生器和标签提取器四个功能模块,实现了用户漫游时的单次认证策略,减小了因重复认证造成的开销。利用Open SER实现了IMS中各个实体的功能,搭建了简易的IMS仿真环境,然后在仿真网络中对跨域信任机制进行验证。仿真结果表明,跨域信任机制减少了0.417 7 s的时间开销。 相似文献
2.
3G IP多媒体子系统(IMS)中采用会话发起协议(SIP)建立和维护多媒体会话,然而,SIP是基于文本的协议,在会话建立过程中需要传输大量的数据,导致会话建立时延的增加。对经典的LZW算法进行改进,将LZW与HUFFMAN算法和静态字典相结合,提出S-LZW-HUFFMAN算法实现对SIP消息的压缩。仿真结果表明,新算法比目前标准化组织建议采用的压缩算法具有更高的压缩效率,能够有效降低传输时延,缩短IMS中基于SIP的会话建立时延。 相似文献
3.
IP多媒体子系统用于实现端到端的IP多媒体通信,具有接入无关性、对各种接入技术广适性的特点,因此,下一代网络采用IP多媒体子系统作为核心架构.提出一个基于IP多媒体子系统的IP电视架构,在IP多媒体子系统核心模块的基础上,以一组互相独立的基于会话初始化协议的功能模块构成应用服务器,并设计了能够支持和提供不同IM S业务的客户端与内容提供商端,使该IPTV框架可以在下一代网络上支持基于IP多媒体子系统的包括IPTV业务在内的多种多媒体业务. 相似文献
4.
5.
IMS可以针对用户不同的需求提供广泛的增值多媒体业务,通过专门的SIP应用服务器可以在IMS网络之上实现这些业务。本文主要讨论当用户获得一个IMS订购关系且其订购关系包含一些增值业务时,如何创建业务专用的数据即过滤规则;当用户在IMS网络上发起业务请求时,通过业务控制机制将SIP请求正确的路由到应用服务器,以执行相应的业务逻辑。 相似文献
6.
7.
8.
9.
10.
11.
Richard Good Fabricio Carvalho de Gouveia Shengyao Chen Neco Ventura Thomas Magedanz 《Journal of Network and Systems Management》2008,16(2):129-144
This paper presents state-of-the-art research efforts in implementing a Policy Based architecture for Quality of Service management
and provisioning of network services in the IP Multimedia Subsystem (IMS). While Policy Based Network Management has been
adopted by the Third Generation Partnership Project and the Telecoms & Internet converged Services & Protocols for Advanced
Networks as the solution for managing QoS in the IMS, the proposed mechanisms are sorely lacking in many aspects. First, the
policy logic and decision mechanism are not specified, nor is the actual resource allocation procedure. Second, while the
IMS is being tailored as the Service Delivery Platform for Next Generation Networks many of the QoS provisioning solutions
are designed specifically for UMTS as an access network and need to be enhanced to support other technologies. In the current
specifications, 3GPP is already evolving to support Packet Cable, WLAN and WiMAX accesses, but their respective policy-related
sections are still void. Furthermore the proposed solutions do not specify how the network processes user requests for services
in the IMS infrastructure. This article analyses critical QoS management issues within the IMS, and proposes solutions by
designing a Policy Decision Function, which is the central element in the policy architecture. These solutions are presented
in a proof of concept implementation running in a real IMS testbed making use of the Open Source IMS Core and considering
the management of QoS in different scenarios.
相似文献
Neco VenturaEmail: |
12.
13.
14.
15.
16.
17.
基于IP多媒体子系统(IMS)的IPTV引入集中式SIP会话管理机制,除对业务控制功能(SCF)服务器提出更高的响应性能要求,而且由于SIP的事务和对话双重完整性,对传统负载均衡技术也带来诸多限制。针对SCF的性能瓶颈,结合IMS的业务触发过程和IPTV业务的会话统计特性,探讨了集群间区分业务和集群内对后台服务器负载感知的多级负载均衡机制,并提出基于SIP事务优先级的轻量级动态权值随机调度算法。最后在IPTV原型系统中验证了该负载均衡机制的技术可行性,并给出具体实验方案。 相似文献