[asterisk-users] T1 timing errors (Frame Slips) on Nortel 61C to TE110P

[Rich Adamson]

Ronnie Jones wrote:
> I am setting up an asterisk box , my first with PRI T1 interface to a 
> Nortel 61C.  We have quite a bit of experience with the 61C and do most 
> of the programming including maintaining several other PRI interfaces in 
> this switch.  The problem we are having is as soon as we turn up the 
> PRI, on the 61C side we get PRI0264 protocol errors.  Then the circuit 
> lays down properly.  At this point we start accumulating SLIPR in the 
> 61C which resets the circuit in about 5 minutes.  Below are my 
> configurations.
> 
>  
> 
> Nortel 61C
> 
>  
> 
>  CEQU
> 
>   MPED 8D
> 
>   TERM
> 
>   REMO
> 
>   TERD
> 
>   REMD
> 
>   TERQ
> 
>   REMQ
> 
>   SUPL 004 012 024 V048
> 
>        N156
> 
>   SUPC
> 
>   SUPF
> 
>   XCT   000  016
> 
>   TDS  * 000 * 016
> 
>   CONF * 001 * 017
> 
>   MFSD * 000 * 016
> 
>  
> 
>   DLOP  NUM DCH FRM TMDI LCMT YALM TRSH
> 
>    TRK  009 12  ESF NO   B8S  FDL  00
> 
>    PRI  008 24  ESF NO   B8S  FDL  00
> 
>         010 24  ESF NO   B8S  FDL  00
> 
>         011 24  ESF NO   B8S  FDL  00
> 
>         018 24  ESF NO   B8S  FDL  00
> 
>         019 24  ESF NO   B8S  FDL  00
> 
>         020 24  ESF NO   B8S  FDL  00
> 
>         021 24  ESF NO   B8S  FDL  00
> 
>         030 24  ESF NO   B8S  FDL  00
> 
>         031 24  ESF NO   B8S  FDL  00
> 
> Blah..blah
> 
>  
> 
> ADAN     DCH 50
> 
>   CTYP MSDL
> 
>   DNUM 10
> 
>   PORT 1
> 
>   DES  ippbx
> 
>   USR  PRI
> 
>   DCHL 8
> 
>   OTBF 32
> 
>   PARM RS422  DTE
> 
>   DRAT 64KC
> 
>   CLOK EXT
> 
>   IFC  ESS5
> 
>   SIDE USR
> 
>   CNEG 1
> 
>   RLS  ID  1
> 
>   RCAP ND2
> 
>   MBGA NO
> 
>   OVLR NO
> 
>   OVLS NO
> 
>   T200 3
> 
>   T203 10
> 
>   N200 3
> 
>   N201 260
> 
>   K    7
> 
>  
> 
> TYPE RDB
> 
> CUST 00
> 
> ROUT 97
> 
> DES  IPPBX
> 
> TKTP TIE
> 
> NPID_TBL_NUM   0
> 
> ESN  NO
> 
> CNVT NO
> 
> SAT  NO
> 
> RCLS INT
> 
> VTRK NO
> 
> DTRK YES
> 
> BRIP NO
> 
> DGTP PRI
> 
> ISDN YES
> 
>     MODE PRA
> 
>     IFC  ESS5
> 
>     SBN  NO
> 
>     PNI  00001
> 
>     SRVC NNSF
> 
>     NCNA YES
> 
>     NCRD YES
> 
>     CHTY BCH
> 
>     CTYP UKWN
> 
>     INAC YES
> 
>     ISAR NO
> 
>     CPUB OFF
> 
>     DAPC NO
> 
>     BCOT 0
> 
> DSEL VOD
> 
> PTYP PRI
> 
> AUTO NO
> 
> DNIS NO
> 
> DCDR NO
> 
> ICOG IAO
> 
> SRCH LIN
> 
> TRMB YES
> 
> STEP
> 
> ACOD 7997
> 
> TCPP NO
> 
> PII NO
> 
> TARG
> 
> CLEN 1
> 
> BILN NO
> 
> OABS
> 
> INST
> 
> IDC  NO
> 
> DCNO 0 *
> 
> NDNO 0
> 
> DEXT NO
> 
> ANTK
> 
> SIGO STD
> 
> ICIS YES
> 
> TIMR ICF  512
> 
>      OGF  512
> 
>      EOD  13952
> 
>      NRD  10112
> 
>      DDL  70
> 
>      ODT  4096
> 
>      RGV  640
> 
>      GRD  896
> 
>      SFB  3
> 
>      NBS  2048
> 
>  
> 
>  
> 
> PAGE 002
> 
>  
> 
>      NBL  4096
> 
>  
> 
>      IENB  5
> 
>      TFD  0
> 
>      VSS  0
> 
>      VGD  6
> 
> DRNG NO
> 
> CDR  NO
> 
> VRAT NO
> 
> MUS  NO
> 
> RACD NO
> 
> FRL  0 0
> 
> FRL  1 0
> 
> FRL  2 0
> 
> FRL  3 0
> 
> FRL  4 0
> 
> FRL  5 0
> 
> FRL  6 0
> 
> FRL  7 0
> 
> OHQ  NO
> 
> OHQT 00
> 
> CBQ  NO
> 
> AUTH NO
> 
> TDET NO
> 
> TTBL 0
> 
> ATAN NO
> 
> PLEV 2
> 
> ALRM NO
> 
> ART  0
> 
> SGRP 0
> 
> AACR NO
> 
>  
> 
>  zapata.conf
> 
> [trunkgroups]
> 
>  
> 
> [channels]
> 
> language=en
> 
> context=default
> 
> switchtype=5ess
> 
> signalling=pri_net
> 
> usecallerid=yes
> 
> echocancel=yes
> 
> echocancelwhenbridged=yes
> 
> rxgain=0.0
> 
> txgain=0.0
> 
> musiconhold=default
> 
> group = 1
> 
> channel = 1-23
> 
>  
> 
>  zaptel.conf
> 
> span = 1,1,0,esf,b8zs
> 
> bchan=1-23
> 
> dchan=24
> 
> loadzone = us
> 
> defaultzone=us
> 
>  
> 
> I think the configuration is right.  I have tried changing the timimg 
> source in zaptel.conf from 1 to 0 to no avail.  Also I can not set up 
> the Nortel PRI to look internal for clock.  Nortel sets up by default 
> CLOK = EXT.  I have tried different cross over cables.  I can point the 
> asterisk into a T-Berd 950N set up to turn up a PRI and it will work and 
> run clean on the Asterisk server.  I can loop back the Nortel PRI and it 
> will ‘est wrong mode’ and accumulate no SLIPR.  I am struggling to get 
> this to work.  The circuit does establish and pass calls but resets 
> frequently due to slips.  Dell 2850/TE110P/Asterisk business edition 
> ABE-B.1-1/Redhat EL4/Nortel 61C/Succession R3/MSDL Dchannel/NT5D12.  Any 
> help would be appreciated.

I have no experience on the Nortel side, but will comment on the timing 
thingie.

The asterisk T1 card (port going to the Nortel) will always generate T1 
timing on the transmit side of the T1. There is no way to turn it off 
(by T1 Spec's). So, letting the Nortel use CLOK = EXT is perfect.

The sync parameter in /etc/zaptel.conf for that same T1 port should 
probably be set to zero, but that statement is somewhat dependent on 
what the other ports on the Asterisk T1 card are used for. If there are 
no other Asterisk T1 card ports in use, then I'd suggest setting the 
sync parameter to "1".  If at least one other Asterisk T1 port is in use 
and goes to a central office, then turn that port's sync to "1" and the 
Nortel port sync to "0". (Keep in mind the digium T1 cards only have one 
clock on board, and syncing that clock to a T1 coming from a central 
office is the right thing to do. Once that clock is in sync, then the 
Nortel will sync to asterisk.)

I'm a little confused with your last paragraph when you say "the circuit 
does establish and pass calls but resets frequently due to slips". Are 
those calls to/from asterisk talking to the Nortel? Or, are you routing 
incoming pstn calls from the central office through asterisk to the Nortel?

Also, have you tried any of the "pri show ..." commands in asterisk, or 
any of the pri debug items?