Incoming fax from PSTN does not work intermittent.(only 5 -6 attempts succeds out of 9)

[devraj123]

Hi All,

Having issue with FAX:

call flow-

FAX-------PSTN---------- MGCP gateway -------------CUCM 9.x------------Sip trunk------------------------Right FAX server

Incoming fax from PSTN does not work , its intermittent not everyday.(only 5 -6 attempts succeeds out of 9)

we have 3 numbers for Faxes 3607-0382, 3607-0384 and 3607-0386

when PSTN user dials thses numbers then some fax misses. I mean PSTN sent 9 faxes but received only 5.

attached Gateway configuration + CUCM logs,

[Ryan Huff]

Under voice service voip, switch to:

fax protocol t38 version 0 ls-redundancy 5 hs-redundancy 2 fallback g711ulaw

Under global config mode:

no mgcp fax t38 ecm
mgcp fax rate 14400
mgcp fax-relay sg3-to-g3

After that, do a "no mgcp / mgcp" restart on the gateway and then reset the gateway config in UC manager. If the issue still hasn't improved, remove the T.38 packet redundancy

no mgcp fax t38 ls_redundancy 5
no mgcp fax t38 hs_redundancy 2

Give that a go and let me know the results :)

Thanks,

Ryan

(.. Please rate helpful posts ..)

[devraj123]

Hi Ryan,

Seems not worked.

devraj