Fax issues are the bane of my existance. It never ceases to amaze me how difficult it can be to get them to work sometimes.
A brief history of fax machines :
Years ago, the ancients developed a technology for sending images across standard telephone lines. Man called it Fax.  Somewhere around the time man discovered fire, this technology was found to be obsolete. But for some reason continued to use it. Even with newer high-speed data connections capable of transmitting color images of much greater detail at speeds thousands of times faster with less error, there are some that cling to the fax technology like a floating piece of wood in piranha infested waters. The log won’t save them from the piranha, but they cling to it anyway.
If, for some unholy reason, you must use faxes on a VoIP network. Fax relay is the way to go.
The problem is that it’s not 100% compatible with callmanager 4 and 5. Cisco got this fixed with version 6 and above.
In order to make fax relay work properly on MGCP controlled voice gateways, the following command should appear in the config:
mgcp fax t38 gateway force
This command will cause the gateways to negotiate the fax-relay themselves rather than rely on the call processing system (callmanager).
If you need to do the same thing with H.323or SIP the command is
voice service voip
fax protocol t38 nse force
And just like that… it’s 2 weeks have passed. I can’t believe how much I’ve had to do at home and work. I really mean to keep this updated daily, but somehow things just make their way on top of the priority list.
This last week we were having issues with some VG224s interoperating with fax machines. One technician noted that the line voltage was only 38 volts. Many fax machines, particularly the older ones, and other devices do not work properly or at all with voltages as low as 38.
The fix for this is simple, the following command placed under the voice-port configuration will increase the idle voltage of the VG224 port to a more acceptable level.
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And so it begins again… the helplessly frustrating, yet incredibly entertaining monotony we call work.
Regularly scheduled updates, including new challenges, will begin this week… stay tuned…
My family and I have recently embarked on a vacation to Japan. The trip was much easier than I thought it would be with 3 young children. There were some very interesting changes though with Swine Influenza spreading. We had a long layover in Taiwan and when we left the aircraft, there were a very good deal of people wearing masks in the airport. Probably a good idea even without an influenza scare since there are people in the airport from all over the world. Our arrival in Japan, however, was even more involved. Before passing through customs, we were required to fill out a document regarding our recent health and travel. Since we were coming from the U.S. we were further required to undergo a simple health check. Apparently on some flights, the health inspectors actually board the flight and check people before allowing anyone to leave the plane.
Recently I was asked by a customer to deliver .wav files to the inbox of their mail server from a Unity Connection server. Well, by asked I mean that the salesperson promised it to them and I had to find a way to deliver it.
I came up with an idea to do this… it didn’t work. But the idea was sound, it just needed a little tuning to make it work right.
I used a Linux server with PHP and Postfix to make all the magic work. It also helped that none of the customers used Unity Connection’s web client.
I created aliases on the Postfix server redirecting users to a custom script. The script then logs into the Unity Connection system and retrieves the .wav file and retransmits it as a new message to a specified email address.
I’m still polishing it up a bit, but it’s fully functional and delivering .wav files to our inboxes as expected. When I get it to a more flexible format I’ll release it on this site. For now, if you are interested and don’t mind a ‘beta’ version of the software, let me know and I can provide you with a copy and instructions for use.
Well, this weeks challenge never made it to the web. I wasn’t happy with the way it was turning out. I’m rethinking how I want to do them to try to save time and provide better study material. Look for new challenges in the next few weeks. We’re heading out on vacation for the next two weeks, so updates will be sparse. But I’m hoping to have a better idea of exactly what I want to do after a few weeks of letting my brain out of the frypan.
Here’s the solution to Challenge 2
Now the problem… I’m still working on Challenge 3, but can barely keep my eyes open. To ensure the quality of Challenge 3, I’ll be posting it tomorrow. Sorry for the delay.
This week has just been too busy. I was working from the time I got up to the time I passed out for the night. Next week I expect to be posting regularly again.
I’m finishing up this weeks lab and will post it later tonight. Sorry for the delay.
Here’s the answers to Challenge 1 : Answers 1
And here’s the next one, Challenge 2 : Challenge 2
I am rarely very impressed with 3rd Party software, but Agito Networks has impressed me. I spent most of my day working with their team to integrate and test their Mobile Router with our IP Telephony platform.  Their solution integrates with most IP Telephony systems and wireless platforms to create a nearly seamless roaming functionality between the corporate environment and wifi enabled cell phones.
Their system allows your cell phone to ring as if it shared a line with your desk phone. You can pick up calls on either cell or desk phones. When you’re within range of a wifi access point, the phone will connect using IP Telephony rather than cellular service. When you’re out of range, it uses cellular. This saves minutes and LD costs on your cellular account. The really cool thing is that the platform can switch from wifi to cellular without dropping your call! In most cases you may not even be aware of the transition.
There are also several other features like corporate directory integration which would allow your cell phone access to the corporate directory stored on your office telephone system.
For anyone interested in taking a closer look, you can find more information about Agito Networks Mobile Router here
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