scope:

Scope, Purpose and Application

This document specifies classes of Quality of Service (QOS) sufficient to support Business Multimedia Conferencing on Internet Protocol (IP) networks, defined as equivalent to legacy conference system performance (e.g., H.320 at Basic Rate Interface (BRI) rates).

It also specifies the threshold of perceptible impairment for some user interface parameters. This standard applies to communications between a subset of multimedia end-points, namely Video Teleconference room systems and Desktop systems.

The current scope is limited to H.323 point-to-point communication (Multipoint communication is for further study).

It applies to cases where IP is utilized between the end-points (e.g., IP/Circuit-Switched Hybrid Network connections are for further study, e.g. networks supporting H.320-compliant terminals).

Figure 1 includes equivalent ITU-T terms in parentheses (Teleservice and Bearer Service). A Teleservice provides a complete user-to-user communications capability, while Bearer Services provide the transport of signals between network interfaces, and do not include the customer's terminal equipment or local network. Furthermore, the Network Interface shown in Figure 1 is equivalent to the ITU-T user-network interface.

All networks in the Figure are not necessarily identical, especially in regards to the position of functions such as authentication and billing. Resources (e.g., capacity) may be reserved on some networks comprising the connection, and not on others. Some networks may not be IProuted networks, e.g., dedicated lines, frame relay networks, and other networks where routers are not present within the administrative boundaries (shown as [R] in Figure 1).

The user-to-user QOS is dependent on the quality and performance of all components that work to establish, or comprise the media connection.

This standard will identify objectives for the user-to-user connection, and allocate portions to the Customer Installation (TE and LAN) and end-end network components. There are different suppliers for terminal equipment and network services, and the allocation will assure that the intended user-to-user performance levels are achieved. It will not allocate portions to individual network providers.

The following are intended uses for this standard:

1. Network planning.

2. Network and Customer Installation component development.

3. User-to-User connection planning.

In connection with User-to-User connection planning activities (item 3), it is necessary to stipulate the desired system type(s). Further, there are cases where certain measurement procedures must be agreed to in advance, since the standardized measurement coverage was incomplete at the time this standard was developed. Although this standard specifies IP network performance parameters, some Non-IP services procured must be evaluated using alternate parameter sets. Draft ITU-T Recommendation I.381, in development at the time this standard was prepared, provides a mapping between the IP layer and lower layer parameters. Another consideration is whether the Acceptable Level specified in this standard is the goal.

When referenced for procurement purposes, the purchaser should specify which values of tables 5 through 12 apply.