[Asterisk-Users] Identifying Frame Slips from PRI debug

[ewr at erols.com]

> Just to clarify, the frame slips are on the T1 circuit which 
> is delivering your PRI service.
That is correct.

> If you are correctly adjusting your timing leaving to match 
> the recevieved timing from the CO there will be no slips. I 
> am unaware of any mechanism within an * server to report 
> this. Of course T-BERDs are your friend in these cases:) I 
> would suggest checking with Digium on your cards and any suggestions.
The zaptel.conf is set to:
span=1,1,0,esf,b8zs
bchan=1-23
dchan=24

My understanding is that the 2nd "1" in the span line means that the TE110P
card should recieve it's sync from the CO.

Do you have a recommendation on a specific T-BERD?  (I had to look up what
it was, but it appears a number are available on ebay for < $1000.)

I honestly wouldn't have known there was a problem if the phone company
hadn't contacted me to tell me there was an extremely high number of
frame-slips occurring.  They came onsite and tested the the PRI from the
smart-jack, including doing loopback tests to their switch.  All of their
testing showed the line as very clean.  The two PRIs we have with them (at
different locations) have similar Dell/T100P (or TE110P) setups, and they
are both experiencing this high number of errors.

I don't understand T1's well enough (yet) to decipher the "pri intense debug
span 1" output, but thought that maybe someone could explain what some of
the output means.  Following is a little bit of the ouput from one of the
machines.  I just took it from the console.  It is 1:30AM here so there are
no calls on the system.  It spits out a set of the following messages every
10 seconds or so.  Is that normal?

elflasterisk*CLI>
T203 counter expired, sending RR and scheduling T203 again
 Sending Receiver Ready (46)

> [ 00 01 01 5d ]

> Supervisory frame:
 > SAPI: 00  C/R: 0 EA: 0
>  TEI: 000        EA: 1
 > Zero: 0     S: 0 01: 1  [ RR (receive ready) ]
> N(R): 046 P/F: 1
> 0 bytes of data
 -- Restarting T203 counter
elflasterisk*CLI>
< [ 00 01 01 d1 ]

< Supervisory frame:
 < SAPI: 00  C/R: 0 EA: 0
<  TEI: 000        EA: 1
 < Zero: 0     S: 0 01: 1  [ RR (receive ready) ]
< N(R): 104 P/F: 1
< 0 bytes of data
 -- ACKing all packets from 103 to (but not including) 104
 -- Since there was nothing left, stopping T200 counter
 -- Stopping T203 counter since we got an ACK
 -- Nothing left, starting T203 counter
 -- Got RR response to our frame
 -- Restarting T203 counter
elflasterisk*CLI>


> Let us know if there is a tool to report. zttool only reports 
> bpv errors. There are many more in the ANSI suite.
> 
> 
> On Dec 21, 2005, at 2:06 PM, <ewr at erols.com> <ewr at erols.com> wrote:
> 
> >>> 		Can someone help me understand how to identify 
> frame slips
> > from "pri debug",
> >>> 		"pri intense debug", or any other method?
> >>>
> >>> 		I am familiar with zttest, avoiding interrupt sharing,
> > mucking with ACPI,
> >>> 		making sure DMA is on, etc... I have a list of changes I
> > intend to make to
> >>> 		the server(s), but don't know how to actually watch the
> > output to see if my
> >>> 		changes are affecting the # of frame slips.
> >>
> >> 	First things first;
> >> 	Check your timing param in zaptel.conf, you almost 
> certainly want
> >> 	it set to 1 if you are connecting that span to a phone 
> company and
> > it is
> >> 	the only such connection on that board.
> >
> > The timing is already set to 1 for each of the cards.
> >
> > I'm still open to ideas on how to actually identify or count frame- 
> > slips on the pri.
> >
> > Eric
> >
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