Hi again Bernie, If you are talking about the E1 implementation of R2, then the Q.421 Recommendation should define everything you need to know. Basically it uses the abcd bits in fairly typical CAS fashion, but the "ab" (i.e. af and bf) bits are used to indicate the status of the forward channel and the "cd" (i.e. ab and bb) are used to indicate the status of the backward channel.
>From Recommendation Q.421: "The digital version of System R2 line signalling uses two signalling channels in each direction of transmission per speech circuit. These signalling channels are referred to as a f and b f for the forward direction (i.e. the direction of call set-up) and a b and b b for the backward direction. Under normal conditions: - The a f channel identifies the operating condition of the outgoing switching equipment and reflects the condition of the calling subscriber+s line. - The b f channel provides a means for indicating a failure in the forward direction to the incoming switching equipment. - The a b channel reflects the condition of the called subscriber+s line (on hook or off hook). - The b b channel indicates the idle or seized state of the incoming switching equipment. The line signals are transmitted link-by-link. The digital version of System R2 line signalling also specifies a means for appropriate action in the case of faulty transmission conditions on the PCM multiplex, see Recommendation Q.424." If you're talking about the analogue "noise-maker" version, then I don't think I can help much. Best regards, Alan Charlton ECI Telecom/Telematics International ---------- From: treg-approval To: treg Subject: R2, thanks but ... List-Post: [email protected] Date: 27 March 1997 17:22 From: NAME: BERNARD MCEWEN FUNC: 10687 Eng Product Certification TEL: 613-274-6500 <BMCEWEN@A1@K> To: MX%"[email protected]"@MRGATE@wpc Treg, Thanks to all those who replied to my R2 question. It is good to have rapid response. Unfortunately, we are already aware that there is a range of Q.4xx series specs on R2, but by looking at the ITU- index list we can not tell which one has the information that we require. We need to identify the spec. that describes the signals in the Backward Direction (ie. the signals that indicate the condition of the called subscriber, such as CALLED PARTY BUSY). We already have a number of the ITU specs. mentioned by those responding, but these do not have the information we require. Can anyone help with "B" signals, in the backward direction? Thanks and best wishes, Bernie McEwen. Regulatory Approvals Manager. Gandalf Canada. 130, Colonnade Road South, Nepean, Ont. K2E 7M4 Telephone: + 1 613 274 6500 Ext 8262 Facsimile: + 1 613 274 6501 / 6506 PS. Alan. Thanks for your note. I am settling in very well in Canada, thanks. As soon as the snow melts and I can see it, I'll let you know what it's like. No doubt all at ICMA are reading this (or having it read to them) so hello, everyone. Why aren't I down to host the Nov-Dec meeting then?
