I have Hylafax+ Version 7.0.2, Cisco SPA112 ATA to send/receive faxes over IP with T.38 (hopefully, T.38 is working) and a couple of multitech modems 9234ZBA.
The setup is quite simple. Hylafax configs for the modems are set to Class1.
I have the following lines in my configs in order to activate ECM:
Class1ECMSupport: Yes
Class1PersistentECM: Yes
Class1ECMFrameSize: 256
Outgoing faxes are flowing just well with ECM enabled.
However, all incoming faxes have no ECM.
I see it from the logs and from fax receipts from Hylafax.
Time To Receive: 0:00:27
Signal Rate: 14400 bit/s
Data Format: 1-D MH
Error Correct: No
Received On: ttyS2
I did 4 test calls:
1)If I send a fax to myself - ECM turns to On on incoming. I have ECM On in the config for outgoing faxes.
2)If I send a fax to myself - ECM turns to On on incoming. I have ECM lines commented out in the config for outgoing faxes, so I assume ECM is set to On by the receiving side (exactly, what I want).
3) I do ECM test for incoming faxes from www.t38fax.com - they report ECM is not enforced on my fax number.
4) If I run outgoing test to www.t38fax.com number - they report ECM is On for my my outgoing faxes.
Sorry for the long explanation.
Is there any way for me to enforce ECM on incoming if the calling party supports it ?
What are the settings for Class1 or any other Class setups so I can be sure that ECM is used if supported by a calling party ?
Thanks, Serguei.
If you would like to refer to this comment somewhere else in this project, copy and paste the following link:
Senders that support ECM will almost certainly use ECM if they see that the receiver supports ECM. So, if a sender isn't using ECM when they could, it's almost a guarantee that they don't see that the receiver supports it.
The most likely culprit is that some T.38 gateway involved is removing ECM support from the communication. Recognize that when T.38 is involved the endpoints are not talking directly to each other. Instead, they are talking to the T.38 gateways closest to them. All it takes, then is for one or both of those T.38 gateways to disable ECM, and ECM will not happen. It is very common for T.38 gateways to disable ECM.
If you would like to refer to this comment somewhere else in this project, copy and paste the following link:
Hello,
I have Hylafax+ Version 7.0.2, Cisco SPA112 ATA to send/receive faxes over IP with T.38 (hopefully, T.38 is working) and a couple of multitech modems 9234ZBA.
The setup is quite simple. Hylafax configs for the modems are set to Class1.
I have the following lines in my configs in order to activate ECM:
Class1ECMSupport: Yes
Class1PersistentECM: Yes
Class1ECMFrameSize: 256
Outgoing faxes are flowing just well with ECM enabled.
However, all incoming faxes have no ECM.
I see it from the logs and from fax receipts from Hylafax.
Time To Receive: 0:00:27
Signal Rate: 14400 bit/s
Data Format: 1-D MH
Error Correct: No
Received On: ttyS2
I did 4 test calls:
1)If I send a fax to myself - ECM turns to On on incoming. I have ECM On in the config for outgoing faxes.
2)If I send a fax to myself - ECM turns to On on incoming. I have ECM lines commented out in the config for outgoing faxes, so I assume ECM is set to On by the receiving side (exactly, what I want).
3) I do ECM test for incoming faxes from www.t38fax.com - they report ECM is not enforced on my fax number.
4) If I run outgoing test to www.t38fax.com number - they report ECM is On for my my outgoing faxes.
Sorry for the long explanation.
Is there any way for me to enforce ECM on incoming if the calling party supports it ?
What are the settings for Class1 or any other Class setups so I can be sure that ECM is used if supported by a calling party ?
Thanks, Serguei.
Senders that support ECM will almost certainly use ECM if they see that the receiver supports ECM. So, if a sender isn't using ECM when they could, it's almost a guarantee that they don't see that the receiver supports it.
The most likely culprit is that some T.38 gateway involved is removing ECM support from the communication. Recognize that when T.38 is involved the endpoints are not talking directly to each other. Instead, they are talking to the T.38 gateways closest to them. All it takes, then is for one or both of those T.38 gateways to disable ECM, and ECM will not happen. It is very common for T.38 gateways to disable ECM.
Thanks for the great explanation, Lee.