Description

Anomaly is seen with a compressed fractional T1 VCOMP bundle configuration in CTPOS version 6.6R1 or higher.

Solution

If a VCOMP bundle is configured on a fractional T1 bundle running CTPOS 6.6R1 or higher using compression, the bundle will not pass traffic and no receive clock will be seen by the end equipment.  For a VCOMP Fractional T1 bundle, the CTP slot configuration would need to have a CTP2000-IM-8P-T1E1 card in slot 0 and a COMPRESSION card in slots 1 or 2. 

CTPOS versions 6.1R7 to 6.5R4 does work correctly for this type of bundle configuration.  Also, the VCOMP bundle will show that it is passing traffic when a bundle query is performed, which is misleading because it will not pass end user traffic. This issue is expected to be fixed in version 7.3R6. 

Workaround:

  1. Configure a CTP type bundle for the same DS0s/T1 port that you want to use for the VCOMP bundle
  2. Activate it
  3. Disable and delete it
  4. Replace it with a VCOMP bundle using the same T1 port and DS0s
  5. It will pass end user traffic until the CTP is rebooted, at which point you must repeat these steps to get it to work again


Here is a bundle query (frac T1 with 3 DS0's using compression) which has the issue: 

########### Bundle 0 type    VCOMP ############

--------- Bundle 0 Config ---------
DBase State:         ACTIVE
Remote Addr:         192.168.1.2
Remote CID:          249
Packet size:         59
Buf Max/Set/Min(ms): 30/20/10
IP Hdr TOS:          0 (decimal)
DSP Companding:      Mu-Law
Voice codec:         G.729AB (8k)
Bundle Source:               00: te-0/0/1   01: te-0/0/2   02: te-0/0/3   
                             
Bndl Desc:      
VC Bndl Cfg Flags:   ---

---------- Port te-0/0 is voice source ---------
Interface type:      T1-B8ZS
Framing type:        ESF
Line Buildout:       ~133 ft
Clock Config:        CTP is Clock Source
Port Desc:      

--------- Bundle 0 State ----------
Runtime State:      ACTIVE

DSP Info(dsp/bndl): 0/0
T1E1 flags:          No_Alarm

--------- Bundle 0 Counters -------
I/F bound packets:   31569
NET bound packets:   31569
LOF Occurence:       0
Missing pkts:        0
Buffer underflows:   0
Buffer overflows:    1
Buffer starves:      0
Buffer average (ms): 20
Last counter clear:  0wk, 0d, 0h, 5m, 15s