Cell Relay Archive

["Saso Stojanovski" <sasos@nortelnetworks.com>]

xu,

i did mean *CAS*.

a special structure is needed for CAS, in order to accomodate the associated
signalling.

otherwise (i.e. if you use CCS), you can emulate voice channels only, because
the signalling anyway goes through a separate (common) channel.

cheers,
    v
--saso



XuHonggang wrote:

> Hi,saso
> I think you mean CCS, of course,a stucture should include it, I just
> try to explain the relation between a sample and a octet, since the
> relation will decide how to design your buffer and tx/rx schedule.
> By the way, is there anyone here really using AAL1 in carrier network?
> I curious.
> regards
> honggang
> -----Original Message-----
> From: Saso Stojanovski <sasos@nortelnetworks.com>
> To: XuHonggang <xuhg@cet.st.com.sg>
> Cc: Nuzhath Shereen <shereen@chequemail.com>; rajagopalan.sampath@wipro.com
> <rajagopalan.sampath@wipro.com>; cell-relay <cell-relay@cell.onecall.net>
> Date: Friday, July 28, 2000 11:01 PM
> Subject: Re: CR: Structured Data Transfer in AAL Type 1 !
>
> >xu,
> >
> >
> >just two remarks:
> >
> >   1) both af-vtoa-0078 and I.363.1 tend to agree that:
> >
> >"The P[ointer] format is used *exactly once* in every cycle, where a cycle
> is
> >the sequence of consecutive SAR-PDUs with sequence count values 0 through
> 7."
> >
> >as i understand it, even if your structure appears several times within the
> >block of 8 consecutive payloads (4 x (46 + 47) = 384 octets), you should
> use
> >the pointer only once.
> >
> >   2) the structure size octets equals the number of voice channels only if
> you
> >use circuit emulation without CAS; otherwise, the structure size is much
> larger
> >(see af-vtoa-0078).
> >
> >
> >cheers,
> >    v
> >--saso
> >
> >
> >
> >
> >XuHonggang wrote:
> >
> >> Hi,
> >> Pointer field is 7 bits, so max offset which it can idicate is 127 Octets
> >> which < 3 ATM cells p and > 2 ATM cells, so standard maker decided to use
> 96
> >> as max number wich align with 2 ATM cells.
> >> You put a pointer in no.0 cell, it can cover all possible offset in no.0
> and
> >> no.1, so second pointer only need to appear in no.2, the same thing
> happen
> >> to no.4 and no.6 cell.
> >> Yes, a octet means 8 bits, means one sample of a voice channel. How many
> >> octets
> >> in your structure means how many voice channels in your structure.
> >> wish it help
> >> XuHonggang
> >> SwitchingSystemDepartment
> >> CET Techologies of Singapore Technologies
> >> 24 AngMoKio Str. 65
> >> Singapore 569061
> >> -----Original Message-----
> >> From: Nuzhath Shereen <shereen@chequemail.com>
> >> To: sasos@nortelnetworks.com <sasos@nortelnetworks.com>
> >> Cc: rajagopalan.sampath@wipro.com <rajagopalan.sampath@wipro.com>;
> >> cell-relay@cell.onecall.net <cell-relay@cell.onecall.net>
> >> Date: Thursday, July 27, 2000 5:26 PM
> >> Subject: Re: CR: Structured Data Transfer in AAL Type 1 !
> >>
> >> >
> >> >
> >> >Hello Saso,
> >> >
> >> >Can you explain more about this SDT format. The ITU-T I.363.1  says that
> >> the pointer format may be used only if the sequence count value is 0,2,4
> or
> >> 6. This is because the 1,3,5 and 7 values are reserved for SRTS.
> >> >
> >> > I didn't understand the rest of the explanation in the standard. What
> is
> >> this 93-octet payload it refers to. By octet, Is it referring to one
> 64kps
> >> channel (I had read that somewhere) or is the digital 8 bits.
> >
> >
> >