pment houses multiple functions within a single product. Some manufacturers and users observe that these prod- ucts have less flexibility and are less likely to interoperate with other products that equipment having a single function. Others are of the opinion that there are natural groupings of functions that should occur and choose to build a product that represents that natural grouping. Where The Network Components Are Located The signaling gateway and media gateway must be deployed at the boundary between the PSTN and the softswitch. All other components may be located anywhere in the network that makes sense with regard to the latency of access, co-location of control and other operational considerations. Note: Latency affects the pace of the conversation. Hu- mans can tolerate a maximum of 250 milliseconds of latency (time delay) before it has a noticeable effect on the quality of the conversation. In particular, media servers may be deployed at the edge or at the core of the network. Deploying media servers at the edge, alongside gateways makes sense when minimization of network traffic is important and when the gateway cluster is large enough to justify its own media server. The Telecom Handbook 2 153 CONVERGENCE OF VOICE & DATA Proxy Servers A proxy is an application running on a gateway that relays packets between a trusted "client" and an untrusted "host." A proxy server is software that runs on a PC, allocating IP addresses to users as they need them to access the high speed Internet connection. It may be viewed as the "corporate telephone system" for Internet access. In addition to managing access to the Internet, the proxy server also acts as a firewall, preventing unwanted intrusion from the Internet into your corporate computer network. - Compliments of Newton's Telecom Dictionary Deploying the media server in the core, alongside applica- tion servers is useful in the early stages of network deployment when network bandwidth is relatively inexpensive. Communications Servers Replacing The "Mainfra