VC-295

Configuring H.323 Gatekeepers and Proxies

H.323 Gatekeeper Features

To enable the gatekeeper to select the appropriate hop-off gateway, use the gw-type-prefixcommand to configure technology or gateway-type prefixes. Select technology prefixes to denote different types or classes of gateways. The gateways are then configured to register with their gatekeepers using these technology prefixes.

For example, voice gateways might register with technology prefix 1#, and H.320 gateways might register with technology prefix 2#. If there are several gateways of the same type, configure them to register with the same prefix type. By having them register with the same prefix type, the gatekeeper treats the gateways as a pool out of which a random selection is made whenever a call for that prefix type arrives. If a gateway can serve more than one type of hop-off technology, it can register more than one prefix type with the gatekeeper.

Callers will need to know the technology prefixes that are defined. The callers will need to know the type of device they are trying to reach and will need to prepend the appropriate technology prefix to the destination address to indicate the type of gateway needed to reach the destination.

For example, callers might request 1#2125551111 if they know that address 2125551111 is for a telephone and that the technology prefix for voice gateways is 1#. The voice gateway is configured with a dial peer (using the dial-peercommand) so that when the gateway receives the call for 1#2125551111, it strips off the technology prefix 1# and bridges the next leg of the call to the telephone at 2125551111.

In cases in which the call scenario is as shown in Figure 57, voice-gw1 can be configured to prepend the voice technology prefix 1# so that the use of technology prefixes is completely transparent to the caller.

Figure 57	Call Scenario
PSTN		H.323 network	PSTN

Telephone

voice-gw1

voice-gw2

Telephone

13098

Additionally, in using the gw-type-prefixcommand, a particular gateway-type prefix can be defined as the default gateway type to be used for addresses that cannot be resolved. It also forces a technology prefix to always hop off in a particular zone.

If the majority of calls hop off on a particular type of gateway, the gatekeeper can be configured to use that type of gateway as the default type so that callers no longer have to prepend a technology prefix on the address. For example, if voice gateways are mostly used in a network, and all voice gateways have been configured to register with technology prefix 1#, the gatekeeper can be configured to use 1# gateways as the default technology if the following command is entered:

my-gatekeeper(config-gk)#gw-type-prefix 1# default-technology

Now a caller no longer needs to prepend 1# to use a voice gateway. Any address that does not contain an explicit technology prefix will be routed to one of the voice gateways that registered with 1#.

With this default technology definition, a caller could ask the gatekeeper for admission to 2125551111. If the local gatekeeper does not recognize the zone prefix as belonging to any remote zone, it will route the call to one of its local (1#) voice gateways so that the call hops off locally. However, if it knows that gk-ny handles the 212 area code, it can send a location request for 2125551111 to gk-ny. This requires that gk-ny also be configured with some default gateway type prefix and that its voice gateways be registered with that prefix type.

Cisco IOS Voice, Video, and Fax Configuration Guide

VC-289 specifications

Cisco Systems has long been a leader in networking technology, and among its diverse range of products is the VC-289. Designed specifically for enhanced performance in high-demand environments, the VC-289 serves a critical role in supporting the modern networking infrastructure.

One of the standout features of the VC-289 is its scalability. The device is engineered to easily accommodate expanded workloads, ensuring that organizations can grow without the need for frequent upgrades. This scalability is complemented by Cisco's commitment to backward compatibility, allowing businesses to integrate new systems with existing setups seamlessly.

In terms of performance, the VC-289 boasts impressive processing power. With advanced multi-core architecture, it is capable of handling multiple data streams simultaneously, making it ideal for environments that require consistent data flow, such as cloud computing and IoT applications. The device’s high throughput ensures that users experience minimal latency, facilitating quick data transfers even during peak usage times.

Security is another key characteristic of the VC-289. Cisco has integrated robust security protocols that protect against various cyber threats. Through features such as advanced encryption standards and intrusion prevention systems, organizations can ensure that sensitive data remains secure and is not compromised during transmission.

Another notable technology within the VC-289 is its support for software-defined networking (SDN) capabilities. This allows for more flexible network management, enabling IT teams to adapt the network according to evolving business needs. The ability to programmatically control the network also means that businesses can implement changes more rapidly, reducing downtime and improving overall productivity.

The VC-289 is designed with energy efficiency in mind, featuring power-saving modes that help reduce operational costs. This focus on sustainability not only benefits the environment but also appeals to organizations striving to meet corporate social responsibility objectives.

In conclusion, the Cisco Systems VC-289 stands as an exemplary solution for modern networking challenges. With its scalability, performance capabilities, enhanced security features, SDN support, and energy efficiency, it meets the demands of today's fast-paced and ever-evolving technological landscape. Organizations looking to invest in a robust networking solution would do well to consider the VC-289 as a cornerstone of their infrastructure.