User`s manual

SIP User's Manual 11. Special Applications - Metering Tones Relay

Version 5.0 277 December 2006

11 Special Applications - Metering Tones

Relay

The MediaPack FXS and FXO gateways can be used to relay standard 12 or 16 kHz

metering tones over the IP network as illustrated in Figure 11-1 below.

Figure 11-1: Metering Tone Relay Architecture

After a call is established between the FXS and FXO gateways, the PSTN generates 12 or

16 kHz metering tones towards the FXO gateway. The FXO gateway detects these pulses

and relays them, over IP, to the FXS gateway using a proprietary INFO messages (shown

in Figure 11-2). The FXS gateway generates the same pulses to the connected phone.

The parameter ‘MeteringType’ (described in Table 5-35) is used to determine the

frequency of the metering tone (12 kHz (default) or 16 kHz). In addition, the correct (12 or

16 kHz) coefficient must be used for both FXS and FXO gateways.

To enable this feature configure ‘SendMetering2IP = 1’.

The proprietary INFO message used to relay the metering tone pulse contains a ‘Content-

Type: message/Metering’:

Figure 11-2: Proprietary INFO Message for Relaying Metering Tones

INFO sip:108@10.13.83.1 SIP/2.0

Via: SIP/2.0/UDP 10.13.83.2;branch=z9hG4bKacEizRjAa

Max-Forwards: 70

From: "aviad" <sip:201@10.13.83.2>;tag=1c1638621413

To: <sip:108@10.13.83.1;user=phone>;tag=1c1412617336

Call-ID: 2031013892fcCd@10.13.83.2

CSeq: 3 INFO

Contact: <sip:201@10.13.83.2>

Supported: em,timer,replaces,path

Allow:

User-Agent: Audiocodes-Sip-Gateway-MP-114 FXS/v.4.40.0.18700

Content-Type: message/Metering

Content-Length: 0