scope:

The purpose of the present document is the harmonization of loss and level planning between the Pan-European and the North American regions, with a global view and the intent that the present document may be subject to adoption by other regions, in future. An equivalent standard has been published by the North American Telecommunications Industries Association (TIA-912 [1]).

The objective of the present document is to specify a loss plan for IP based networks particularly suitable for use by voice gateway manufacturers operating in Europe.

The recommended loss values are based on:

- Pan-European analogue telephone sets as specified in TBR 038 [3];

- Digital sets as specified in ITU-T Recommendation P.310 [7]; and

- Typical European public network losses.

These loss values may not provide optimum performance in conjunction with network operators whose telephone set loudness ratings or network losses differ significantly from the values used in the present document. Manufacturers may need to modify their loss plans accordingly, but the principles described in the present document provide guidance on how to derive suitable loss values. A spreadsheet is also provided as an annex to assist manufacturers in determining the correct loss values.

The PBX ports referred to in the present document are as defined in ES 201 168 [2] or TIA-912 [1].

NOTE: The present document introduces two variants of the L2 interfaces for transmission planning purposes.

The present document applies to all kind of voice services, irrespective whether they provide:

- real time conversational telecommunication between human subjects; or

- listening-only telecommunication from a machine interface (stored speech) to a human subject; or

- speaking-only telecommunication from a human subject to a machine interface.

The present document is initially limited to voice gateways interfacing to IP telephony networks. For the purposes of the present document, a voice gateway is considered to be a device that performs routing functions between:

- telephones (analogue, digital, IP);

- public and private network trunks;

- IP based networks.

The present document may apply also to loss planning in any purely digital transmission network which may include:

- circuit switched networks;

- frame relay or ATM networks;

- mobile networks.

While the present document does not apply to other services, which may be carried over the same infrastructure, e.g. Voiceband Data or Fax; nevertheless, complying with the present document will, in general, be advantageous for such other services.