VNS Video-Over-IP Guidelines

Gatekeeper Registration Gatekeepers provide network services to H.323 terminals, MCUs, and gateways. H.323 devices register with gatekeepers to send and receive H.323 calls. Gatekeepers give permission to make or accept a call based on a variety of factors. Gatekeepers can provide network services such as: 1.    Controlling the number and type of connections allowed across the network. 2.    Helping to route a call to the correct destination. 3.    Determining and maintaining the network address for incoming calls. When a client subscribes to one of the ITS Video Network Services Video Services their video endpoint is configured to register to the VNS gatekeeper.  Each endpoint is assigned a unique number that follows the ViDeNet dialing scheme.  The (Global) Dialing Scheme (GDS) is a numbering plan for the global video and voice over IP network test bed, developed by ViDeNet. It is sometimes referred to as an E.164 number. It resembles the international telephone system, numbering plan, with some exceptions. With the GDS, you can number each participating videoconferencing endpoint, MCU conference and gateway. GDS provides, uniform dialing throughout the world. Each basic number consists of four parts: < IAC><CC><OP><EN> 1. The International Access Code (IAC) Also called the world gatekeeper prefix. This is defined as 00 2. A Country Code (CC)   This follows the ITU international access code system. For instance, the country code for the Netherlands is 31.  The country code for the United States is 1. 3. An Organizational Prefix (OP) Many national research organizations follow the telephone number system in their country and use their area code and organizational telephone exchange prefix. For instance, The ITS Video Network Services gatekeeper is assigned 1129. Other gatekeepers in the ViDeNet community locate the ITS Video Network Services gatekeeper by using this unique routing number.  The service providers OP MUST be unique within a country. 4. An Endpoint Number (EN) Your EN will be a number assigned to you by ITS Video Network Services.  Each endpoint number MUST be unique within the VNS network. Normally the number assigned by VNS will begin with 555 then 4 digits, which are unique to your video endpoint. The whole numeric number therefore looks like: < IAC><CC><OP><EN> Examples: The ITS Video Network Services Help Desk number is 00(IAC) 1(CC) 1129(OP) 5551000(EN).  Typed into your videoconferencing endpoint, the number would look like:  00111295551000 Registering to the ITS Video Network Services gatekeeper allows other locations to dial your site using both the IP address AND the GDS number.  In cases where your unit is behind a firewall or using NAT, the GDS number may be the only way for someone to dial into your site.