All,

Apologies if you've already seen this email before.

So far, the only suggestion I've received is that no endpoints really use the multirate info correctly and so MCUs/ gateway manufacturers have to have knowledge of the type of H.320 call to make, based on the called number.

It strikes me that having the ability to at least signal the required bandwidth for the call in the H.225 Setup message, even if you don't include WAN specific call setup parameters such as bonding/H.221-aggregration/Hybrid call, could be of value.

What does everyone else think? Michele ---------------------------------------- Michele Bozier Principal Development Engineer Madge Networks, Wexham Springs, Framewood Rd, Wexham, Slough SL3 6PJ, England Tel: +44(0)1753 661331 Fax: +44(0)1753 661011 email:mbozier@madge.com

---------------------------------------- Hi all,

I have a question about how to signal a multiple 'B' channel SCN call from an H.323 endpoint.

The bearer capability information element in standard Q.931 allows you to signal a Multirate call and then specify the bandwidth (in multiples of 64Kbps) using the optional rate multiplier octet (octet # 4.1). My question is how do I signal an n * 'B' channel call from my H.323 endpoint, where the channels are aggregated using H.221 framing or Bonding?

Reading the H.225 standard, the description of the Rate multiplier field indicates that it 'shall' be present if the call is Multirate as per standard Q.931. It then goes on to say that: 'For a call originated from an H.323 endpoint, this SHALL be used to indicate the bandwidth to be used for this call'.

Is this field only mandatory if I am doing Multirate, or is the intention that it should be used to indicate the number of 'B' channels irrespective of how the ISDN call is placed (Multirate,multi-H.221 or Bonded)? (My understanding of pure Q.931 is that it really only ought to be present in the Multirate case).

If I can't use the rate multiplier octet in the non-Multirate case, is there a standard way I can signal a 2 * B, or 6 * B channel call?

Thanks in advance for your help!

Michele Bozier