Cisco Support Community
Showing results for 
Search instead for 
Did you mean: 
New Member

Panasonic KX-TM131 and as5300 fax trouble


I tryed to send fax with T.38 through an as5300 gateway - IOS 12.2(5). The called fax equipment was a Panasonic KX-TM131 fax machine. I wasn't able to send fax - I tryed many-many times.

In Cisco I got:

2w0d: 0:D (20085) 37979490 fr-msg-det NSF

2w0d: 0:D (20085) 37980690 fr-msg-det CSI

2w0d: 0:D (20085) 37981430 fr-msg-det DIS

2w0d: 0:D (20085) 37983050 fr-msg-tx TSI

2w0d: 0:D (20085) 37983700 fr-msg-tx good crc, 23 bytes

2w0d: 0:D (20085) 37983780 fr-msg-tx DCS

2w0d: 0:D (20085) 37989110 fr-msg-det FTT

2w0d: 0:D (20085) 37990540 fr-msg-tx TSI

2w0d: 0:D (20085) 37991180 fr-msg-tx good crc, 23 bytes

2w0d: 0:D (20085) 37991260 fr-msg-tx DCS

2w0d: 0:D (20085) 37996590 fr-msg-det FTT

2w0d: 0:D (20085) 37998020 fr-msg-tx TSI

2w0d: 0:D (20085) 37998660 fr-msg-tx good crc, 23 bytes

2w0d: 0:D (20085) 37998740 fr-msg-tx DCS

2w0d: 0:D (20085) 38006550 fr-msg-tx DCN

On the sender's side I saw, that I didn't get AT+FRH=3 modem command - timeouted. The Cisco gateway DIDN'T send back anything to the sender while it had to. While the sender didn't get back response to FRH=3 (I think in 3 seconds) the line was dropped.

The same situation is time to time - the problem is reproducable. I did also packet sniff for T38 protocol and I saw, that no T38 response packet came from Cisco gateway.

I also tryed to send to the same fax machine with T.37 protocol. With T37 it worked fine:

2w0d: 0:D (20089) 35699126 fr-entered (10ms)

2w0d: 0:D (20089) 35699230 fr-pkt-loss 2

2w0d: 0:D (20089) 35705370 fr-msg-det NSF

2w0d: 0:D (20089) 35706570 fr-msg-det CSI

2w0d: 0:D (20089) 35707320 fr-msg-det DIS

2w0d: 0:D (20089) 35707940 fr-msg-tx TSI

2w0d: 0:D (20089) 35709210 fr-msg-tx DCS

2w0d: 0:D (20089) 35714830 fr-msg-det FTT

2w0d: 0:D (20089) 35715270 fr-msg-tx TSI

2w0d: 0:D (20089) 35716540 fr-msg-tx DCS

2w0d: 0:D (20089) 35722160 fr-msg-det FTT

2w0d: 0:D (20089) 35722610 fr-msg-tx TSI

2w0d: 0:D (20089) 35723880 fr-msg-tx DCS

2w0d: 0:D (20089) 35729500 fr-msg-det FTT

2w0d: 0:D (20089) 35729950 fr-msg-tx TSI

2w0d: 0:D (20089) 35731220 fr-msg-tx DCS

2w0d: 0:D (20089) 35736840 fr-msg-det CFR

2w0d: 0:D (20089) 35784290 fr-msg-tx EOP

2w0d: 0:D (20089) 35786920 fr-msg-det MCF

2w0d: 0:D (20089) 35787360 fr-msg-tx DCN

From this I think, the problem is with T.38 part (not with T.30).

I also tryed to send through an as5350 - IOS 12.2(15)T9 - with T.38 and got the same.

Could anybody help me?

Thanks in advance,



Re: Panasonic KX-TM131 and as5300 fax trouble

Looks like a clock mismatch issue. Try configuring the command "clock source internal" on the gateways on both the ends.

New Member

Re: Panasonic KX-TM131 and as5300 fax trouble

I didn't expected much from changing 'clock source' because problems are ONLY with that destination/fax machine. All of the other destionations are good (I didn't hit a similar situation).

Even so I tryed to change the clock source. Unfortunately it didn't help.

My configuration was:

controller E1 0

clock source internal

pri-group timeslots 1-31


interface Serial0:15

no ip address

isdn switch-type primary-net5

isdn incoming-voice modem

isdn map address .* plan isdn type unknown

isdn T309-enable

isdn T321 40000

isdn T310 20000

isdn sending-complete

no fair-queue

no cdp enable


voice-port 0:D


bearer-cap Speech


dial-peer voice 300 voip

incoming called-number xxxT

voice-class codec 3

fax protocol t38 ls-redundancy 0 hs-redundancy 0

ip precedence 5

no vad


dial-peer voice 301 pots

destination-pattern xxxT


port 0:D

prefix 0


voice class codec 3

codec preference 1 g729r8

codec preference 2 g729br8

codec preference 3 g723ar53

codec preference 4 g723ar63

codec preference 5 g723r53

codec preference 6 g723r63

codec preference 7 g711alaw

codec preference 8 g711ulaw


As I wrote, this configuration works well, just in this one case I have problems (maybe there are more cases just didn't sent enough faxes to find out).

Any help would be appreciated.


CreatePlease to create content