FXS's fax replies only on second attempt

[goranpilat]

Hi all,

Here is the deal: I have two routers 2800 which are connected with ISDN PRI. The First router is under my administration and in this case it acts as providers router. The other router on other side of PRI is business customer's router which has CME installed and one FXS port with fax attached to it. The outbound fax can be sent and this part works well. The problem is with receiving fax which doesn't work. (The call is immediatelly released). Other strange thing I noticed is if I retry the inbound call immediatelly after the first attempt was rejected, I get the fax signal (which was't the case the first time)!! Please help me with any suggestions. Is it problem of my router (provider) or customer's (CME)?

regards,

Goran

[paolo bevilacqua]

Hi,

you might have overlapping DPs. Do "show dialplan number XXX" with the fax number and if you see more than one entry, that is the problem. Also, you have not explained how the fax is attached on your side.

[goranpilat]

Hi Paolo!

Thanks for the reply.

Fax on my side would be any other fax in any other network.

regards,

[paolo bevilacqua]

So the problem is that this customer can receive fax each other call ?

The reason is likely misconfiguration and the furst check is the one I've suggested before.

[goranpilat]

Hi Paolo!

So here is only customer's fax relevant (which is attached to CME by FXS port). This fax can make outbound faxes (FXS->CME->PRI->Provider router->Softswitch....)but the other way doesnt work. When I call this fax machine first time I am immediatelly disconnected and on the next try (the one that is immediatelly after) I get the fax signal. Problem is also that I dont have access to customers CME. I am only interested if everything is fine with the provider's router. I am also sending my dial peers. In this case for inbound faxes I am using 3000 and 4000:

dial-peer voice 1000 pots

description inbound pots (from CME)

incoming called-number .T

direct-inward-dial

!

dial-peer voice 2000 voip

description outbound voip (to SoftSwitch)

translation-profile outgoing ToSoftSwitch

destination-pattern .T

modem passthrough nse codec g711alaw

voice-class codec 1

session protocol sipv2

session target ipv4:X.X.X.X

dtmf-relay h245-alphanumeric h245-signal

fax rate disable

fax protocol pass-through g711alaw

no vad

!

dial-peer voice 3000 pots

description outbound pots (to CME)

translation-profile outgoing ToCME

destination-pattern 12317779...

port 0/1/0:15

!

dial-peer voice 4000 voip

description inbound voip (from SoftSwitch)

modem passthrough nse codec g711alaw

voice-class codec 1

session protocol sipv2

incoming called-number 12317779...

dtmf-relay h245-alphanumeric

fax rate disable

fax protocol pass-through g711alaw

no vad

regards,

goran

[paolo bevilacqua]

Hi,

Likely the problem is not on your side. Check with "debug isdn q931" and you will see that each other (meaning, alternatively) fax call is likely disconnected by your customer with "unknown number".

[goranpilat]

Thanks for the help,

Seems that the fax was malfunctioning. The other machine worked just fine :)

regards,

goran

[paolo bevilacqua]

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