FAX con SPA2102 y SPA3102

Thank you for your reply.

Ok, I report my solution because I think that can be userfull for other users.

I have resolved the problem in this manner:

1) on the SPA 3102 I have set the PSTN Line, audio section:

a) preferred codec G711u;

b) use pref. codec: YES;

c) silence supp. enable: NO;

d) echo canc enable: YES;

e) echo canc. adapt enable: YES;

f) echo sup enable: NO;

g) FAX CED Detect Enable: YES;

h) FAX CNG Detect Enable: YES;

i) FAX Passthru Codec: G711u;

j) FAX Codec Symmetric: YES;

k) FAX Passthru Method: reinvite;

l) FAX Process NSE: YES;

m) FAX Disable ECAN: no

2) on the SPA 2102 on the line were is  attached the fax machine, audio section:

I have followed the setup as described in the document that I have mentioned in my first message that is:

a) Preferred Codec: G711u;

b) Use Pref Codec Only: YES 

c) Silence Supp Enable: NO

d) Echo Canc Enable: NO

e) Echo Canc Adapt Enable: NO

f) Echo Supp Enable: NO

g) FAX CED Detect Enable:YES

h) FAX CNG Detect Enable: YES

i) FAX Passthru Codec: G711u

j) FAX Codec Symmetric: YES

k) FAX Passthru Method: reinvite

l) FAX Process NSE: YES

m) FAX Disable ECAN: NO

n) FAX Enable T38: NO

o) FAX Tone Detect Mode: caller or callee

With this configuration I can receive and send fax to 14.400 on PSTN line acros the asterisk and the SPA 3102 / 2102 device.

The phone attached on the line 1 port of the spa 3102 have not echo when answer or call on the PSTN line as the other phone that have access to PSTN Line.

The phone of the fax macchine have echo, but usualy is not used as phone.

http://homecommunity.cisco.com/t5/VoIP-Adapters/receiving-fax-trought-spa-3102-asterisk-1-4-and-spa2102/m-p/321688