[Asterisk-Dev] single bit T1 errors (Zhone again)

[Don Pobanz]

On Tuesday, April 15, 2003 3:28 PM, Jon Pounder [SMTP:JonP at inline.net] 
wrote:
> 1) does every signaling bit that comes along generate an event in the
> driver, or only the first bit of a given signaling type (ringing,
> hookstate, etc.) ? If so great, if not what handles this part ?

I don't know if this is useful information as it is not driver specific 
but is T1 specific. Framing and channel configuration have an effect on 
signaling states. A signaling state is determined by looking at a 
complete superframe, which will contain 2 or 4 signaling bits.

If framing on a T1 is
ESF -
    4 signaling bits A, B, C and D (16 possible state) -
    superframe is 24 frames long. Signaling come from frames 6,12,18,24
SF -
    2 signaling bits A and B - (4 possible states)
    superframe is 12 frames long. Signaling bits come from frames 6 and 
12.


> 2) do the events in 1) come in at a reliable interval as defined by 
the
> media properties eg: T1 would have a certain fixed event rate per
> channel, and E1 would have another predictable but possibly different 
> rate ?

There would be a reliable interval for the state of a T1, one 
superframe. One frame is 1/8000 of a second (125 micro second). So 
every 1/8000 second there could be a new state.

I have no idea how the driver passes on signaling. It could be bits or 
states or change in states. Also, I do not know if there is any 
performance monitoring that could be used to determine if bits are 
being received in error.

If any of this is useful great, if not sorry to have used the 
bandwidth.

Don Pobanz