Still celebrating National IT Professionals Day with 3 months of free Premium Membership. Use Code ITDAY17

x
?
Solved

Asterisk Fax T.38 Support Explained

Posted on 2009-04-08
8
Medium Priority
?
2,671 Views
Last Modified: 2013-11-12
Could someone explain this to me:

"Asterisk 1.6 support G.711 and T.38 FAX origination and termination. T.38 gateway features are still in development. "

What is gateway features?  What will Asterisk 1.6 actually support with faxing, in layman terms?  Real world scenario examples would be helpful.  Thank You!
0
Comment
Question by:jkockler
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 4
  • 4
8 Comments
 
LVL 16

Accepted Solution

by:
ai_ja_nai earned 2000 total points
ID: 24107130
A fax gateway is a facility that collects all the in/outcoming traffic and routes it to the right places, instead of letting the clients do it in their own place.

In practical scenarios, a T.38 fax call has at least part of the call being carried over PSTN, although this is not required by the T.38 definition, and two T.38 devices can send faxes to each other. This particular type of device is called Internet-Aware Fax device, or IAF, and it is capable of initiating or completing a fax call towards the IP network.

The typical scenario where T.38 is used is - T.38 Fax relay - where a T.30 fax device sends a fax over PSTN to a T.38 Fax gateway which converts or encapsulates the T.30 protocol into T.38 data stream. This is then sent either to a T.38 enabled end point such as fax machine or fax server or another T.38 Gateway that converts it back to PSTN PCM or analog signal and terminates the fax on a T.30 device.
0
 
LVL 4

Author Comment

by:jkockler
ID: 24107722
Great explanation!  Thanks!

Now just a bit more information and I should be good.

I am running Asterisk 1.4.23 which supports T.38 pass through.  Is this enough to get 2 fax machines to talk to each other?  Or should I upgrade to Asterisk 1.6, which supports origination and termination?  I would just test it but the fax machine I have right now doesn't work real well in general, so it is not a good test of function for the Asterisk box.  Thanks Again!
0
 
LVL 16

Assisted Solution

by:ai_ja_nai
ai_ja_nai earned 2000 total points
ID: 24108035
From version 1.4, Asterisk supports T.38 negotiation for SIP users, and the related passthrough of UDPTL T.38 data. This allows many T.38 nodes to communicate through an Asterisk box. Asterisk 1.4 does not, however, understand the T.38 protocol. It cannot terminate T.38 calls, or act as a T.38 PSTN gateway without external support - i.e. by passing the T.38 data to something which can perform those functions.
0
AWS Certified Solutions Architect - Associate

This course has been developed to provide you with the requisite knowledge to not only pass the AWS CSA certification exam but also gain the hands-on experience required to become a qualified AWS Solutions architect working in a real-world environment.

 
LVL 4

Author Comment

by:jkockler
ID: 24108214
Ok but What does terminate T.38 calls mean?  What is T.38 origination and termination?
0
 
LVL 16

Assisted Solution

by:ai_ja_nai
ai_ja_nai earned 2000 total points
ID: 24108827
it's the capability of creating and destroying telephone sessions
0
 
LVL 4

Author Comment

by:jkockler
ID: 24109496
Oh ok, so if the fax machine originates and terminates the call, then there should be no problem with 2 fax machines talking across an asterisk 1.4 box, right?  
0
 
LVL 16

Assisted Solution

by:ai_ja_nai
ai_ja_nai earned 2000 total points
ID: 24110351
yes, because 1.4 can passthrough the calls, but not start and terminate on its own
0
 
LVL 4

Author Comment

by:jkockler
ID: 24112911
That's awesome.  So Asterisk 1.6 can actually send a fax document directly to a fax machine, from itself.  That is really cool.  Thanks man!
0

Featured Post

Does Your Cloud Backup Use Blockchain Technology?

Blockchain technology has already revolutionized finance thanks to Bitcoin. Now it's disrupting other areas, including the realm of data protection. Learn how blockchain is now being used to authenticate backup files and keep them safe from hackers.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Implementing Avaya's One-X portal is pretty painless, until you want to deploy this to the Android and iPhone clients when these clients are outside of your network. The clients will also work within your local network. Here is our experience and so…
Why do some people recommend buying business VoIP from an ISP? What are the benefits to my company? What are the costs?
Get a first impression of how PRTG looks and learn how it works.   This video is a short introduction to PRTG, as an initial overview or as a quick start for new PRTG users.
How to Install VMware Tools in Red Hat Enterprise Linux 6.4 (RHEL 6.4) Step-by-Step Tutorial
Suggested Courses

704 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question