Voice over IP

VoIP Peering: Bridging the Gap Between Public and Private Networks

23. Mai 2002
Bei Voice over IP (VoIP) als kostensparendem Ersatz für herkömmliche Telefonie handelt es sich meist um Insellösungen. Neuerdings mehren sich Angebote, die den zuverlässigen Austausch zwischen verschiedenen Netzen erlauben, so die Yankee Group in ihrem kürzlich veröffentlichten Bericht.

While the industry has seen residential voice-over-Internet Protocol (VoIP) traffic take many forms, from international calling cards to call-back services and other arbitrage opportunities, the ability to peer at a native IP level from the enterprise to the service provider is a recent development. Solutions that address issues such as security and quality of service (QoS) specifically for VoIP have emerged - for example, CPE-based solutions from Cisco and Aravox offering Session Initiated Protocol (SIP)-aware firewalls, and a host of new network-based solutions from Acme Packet, Kagoor, Netrake, NexTone, U4EA, and others. The ability to peer enables service providers to interconnect public VoIP networks with private VoIP networks, encouraging interenterprise and intercarrier transport and services. This body of research seeks to explore the service providers' drivers of and barriers to peering through to the enterprise using native VoIP, as well as peering VoIP traffic between service providers. Within the packetized voice architecture for the service provider there are three distinct deployments of VoIP: IP-PSTN: A call originates at the enterprise as a VoIP call and is converted to TDM either at the customer premises through an on-site gateway, or at the service provider point of presence (POP) through a media gateway. PSTN-IP: A call originates at the enterprise as a PSTN call, and then is converted to a VoIP call through a media gateway in the service provider network. The call is then transported over IP in the core of the service provider network. IP-IP: A call originates at the customer premises as a VoIP call, is passed along to the service provider without conversion to the PSTN, and is consequently peered through to another service provider as a pure VoIP call. This Report focuses on the ability to peer IP?IP for voice without tapping into the PSTN. This would enable service providers to interconnect disparate enterprise networks, thus taking control of the islands of VoIP that have been created through the growing market acceptance of IP PBXs in the large enterprise (see Exhibit 1). This capability will enable the enterprise to communicate not just within its own organization, but also to partners and customers that are VoIP-enabled in their own enterprises. VoIP peering is not a trivial exercise. Obstacles for service providers include firewall penetration for VoIP, Network Address Translation (NAT) compatibility, QoS mediation, H.323-to-SIP interworking, session admission control, and the ability to generate session detail records. The carriers that can conquer these obstacles will be the carriers that grab the market share of the VoIP enabled enterprise business.


Der vollständige Bericht bei der Yankee Group bestellt werden.

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