scope:

The present document provides speech transmission performance requirements for narrowband and wideband media gateways from a QoS perspective as perceived by the user. Media gateways can be network or home based, they may include a transcoding function. The present document covers the following types of IP-based media gateways:

• ATA (Analogue Terminal Adapter), home gateway IP to POTS

• ITA (ISDN Terminal Adapter), home gateway IP to ISDN

• IAD (Integrated Access device), home router including ATA or ITA

• Network based ATA and ITA

• Carrier grade media gateway, network gateway IP to TDM

• IP-to-IP media gateway, network gateway with transcoding and/or other media processing

DECT interfaces of media gateways are excluded from the present document and should be measured according to the relevant DECT standards.

Interfaces of media gateways used together with terminals as a system (i.e. connected via Ethernet or with a proprietary interface) are excluded in the present document and should be measured according to the relevant terminal standard.

If a media gateway includes more than one interface type (e.g. POTS and ISDN), each interface has to be dealt with differently.

The requirements available in the present document will ensure a high compatibility with IP-and TDM-based fixed and wireless terminals and networks, including DECT and mobile terminals.

It is the aim to optimize interoperability, the listening and talking quality and the conversational performance. Related requirements and test methods are defined in the present document.

The present document does not apply to media gateways with 4-wire analogue interfaces.