MODEMS don't work with PRI over AT&T Flex 3

[bobertb]

[highlight #FCE94F]Once you switch over you IpO (and BCM for that matter), any applications using a MODEM will NOT work.[/highlight]
Not sure I would expect any different outcome with other provider's offerings.
I'm hoping someone replies to this and says I'm full of it and has a solution

This is a major headache that you should nip in the bud as soon as you get wind of a customer going this route.

NOTE: This is AT&T router handing off PRI to IpO...not SIP
If you monitor the connection with a Butt Set and use, say, ProComm, this is what happens:
[ul]
[li]ProComm dials out[/li]

http://www.tek-tips.com/threadminder.cfm?pid=940

[li]Far end MODEM answers[/li]
[li]You hear 1/2 second of data[/li]
[li]Procom says "Disconnected" and tries call again.[/li]
[/ul]

This happened to our corporate office when we switched from Time Warner PRI's. We didn't find out right away (like 2 weeks) because our modem needs are sporatic.
I opened a ticket with AT&T. They played around with it for 1.5 weeks. They monkeyed around with router settings, like setting up for G711.
No luck. I've been on vacation. I think ticket is still open.
We are in the process of ordering some 1MB's.

Today I am at another customer that switched to AT&T Flex a year ago.
It is a BCM400. They don't use modems, so I cranked up ProComm for a test.
SAME problem as on the IpO

I have not had any customer complaints regarding FAXING.
I have not tested CREDIT CARD terminals yet, but I sure want to.
I haven't tried this at any CS1000 sites yet.

Also since we upgraded, there are certain IVR systems we can't break into menus with DTMF.
One is an Verizon 800 number we frequently use.
It does work with an analog set as you can push DTMF out for as long as you press the keys.

 

[StubbedmytoeonIPO]

just a guess but it sounds to me like you have a pri timing issue. I know you said no complaints on faxing and that would be a timing tip off. You said Time Warner PRIs. Do you have the timing set on one to Network and the other fallback?

 

[mattKnight]

NOTE: This is AT&T router handing off PRI to IpO...not SIP
[\quote]

The thing is it probably is SIP (almost efijitely IP based) from the Att device to the CO. In that situation the fact that it presents to the ipo as isdn doesn't mean that modems will just work.

All that said ty reducing the baud rate

Take Care

Matt
I have always wished that my computer would be as easy to use as my telephone.
My wish has come true. I no longer know how to use my telephone.

 

[intrigrant]

In my opinion the provider recognise fax calls and invoke the T.38 protocol over their SIP lines, that explains why faxes do work.
If the provider is good then create a user shortcode in the modem user settings like SC=9N TN=N Action=Dial3k1 lineID=the PRI outgoing ID.
That should inform the provider to provide a full 64Kb connection uncompressed which should be good enough for analog modems at max 14k4 speed.

 

[jhall123]

Another option is having the modem send out a caller id that the carrier can recognize and mark that as a modem call. I've had this help with some carriers. They dont apply compression to the calls this way. I've got faxes to work this way. Not had many customers still using modems thankfully. If they have to have the modem your best option is to have a true copper analog line dropped in.

The DTMF issue can usually be fixed by the carrier but how is it setup in your SIP trunk?

 

[bobertb]

Thanks for the responses guys...

Just to clarify.
[ul]
[li]IpO is not using SIP trunking. Using PRI.[/li]
[li]This is the exact same problem I see on a BCM (Avaya Business Communications Manager system)...which you can't manipulate any settings re. Modems[/li]
[li]The Modem connection starts and drops after the first 1/2 second...never a chance (IMHO) for modem negotiation or retraining and or timing to be an issue. It seems the Router sees the data stream and dumps it[/li]
[/ul]

On the IpO...I will try the Short Code trick and see what developes

On a side note...I have seen posts indicating some AT&T reps tell the customers it works with no problem, other posts indicating AT&T rep said it won't work.

 

[tlpeter]

It is not an IPO problem, it is a trunk issue.
Your modem is PRI to the IPO but SIP to the CO.
SIP and modems do not work very well.
But modems are ancient and should not be used anymore.
This is the year 2015, not 1980.

BAZINGA!

I'm not insane, my mother had me tested!

 

[bobertb]

tlpeter...oh yeah..I totally agree. It is 2015...get with the program people .

In 2015, here are the uses I constantly run into where modems are still involved:
[ul]
[li]Alarm Systems[/li]
[li]HVAC systems[/li]
[li]Credit Card Terminals[/li]
[li]Postage Machines calling home[/li]
[li]Router Access[/li]
[li]Industrial Applications where vendors access equipment remotely[/li]
[li]

Customers are more apt to allow dialup access than give them VPN access to their equipment like "Tank level monitoring"​

[/li]
[li]Your application here...[/li]
[/ul]
I visited the US Robotics website today. They are happily selling and promoting modems as an alternative to "costly" network access...lucky us.

 

[bobertb]

This is about similar issues in 2009

http://www.tek-tips.com/viewthread.cfm?qid=1566277

 

[mforrence]

If you monitor the connection with a Butt Set and use, say, ProComm, this is what happens:

ProComm dials out

http://www.tek-tips.com/threadminder.cfm?pid=940

Far end MODEM answers
You hear 1/2 second of data
Procom says "Disconnected" and tries call again.

It MAY be that the gateways hear the modem tone and are trying to re-invite, but something is preventing it. This can happen with IPO and analog fax over SIP. Gateways don't know the difference between fax and modem handshake.

 

[Signo]

In 2015, here are the uses I constantly run into where modems are still involved:
Alarm Systems
HVAC systems
Credit Card Terminals
Postage Machines calling home
Router Access
Industrial Applications where vendors access equipment remotely
Customers are more apt to allow dialup access than give them VPN access to their equipment like "Tank level monitoring"
Your application here...

I visited the US Robotics website today. They are happily selling and promoting modems as an alternative to "costly" network access...lucky us.

I work for a telco and wanted to elaborate on what you are seeing. This is a very touchy subject for me, so I had to put in my 2 cents.

The issues you are seeing using AT&T Flex are industry wide and not just AT&T. As things progress we are all being forced to use delivery methods that utilize VoIP in some fashion. CES or circuit emulation is very common as others have pointed out. Using MPLS networks and some end device to emulate a PRI, is what AT&T flex is. TDM timing over VoIP can be an issue and timing and latency issues are very bad for analog data. There are ways to propagate the timing through the network, but it will never be as good as an old TDM dedicated circuit.

To make matters worse a lot of ageing class 5 switches are end of life and having to be decommissioned. The only logical step in the process is to go to a softswitch solution (MetaSwitch, Broadcom, Genband and others) which makes that old analog line that worked perfect for those applications you run into all the time now a VoIP line on the back end. We use analog forward facing customer equipment that is VoIP on the backhaul. Similar to a CableTV MTA but with much higher port density and at a central location. I recently went though one of these conversions and things that worked perfect for years now have very inconsistent performance. Analog data over VoIP is just not reliable even at the carrier level. A large portion of long distance connectivity is now done through SIP between tandem switches and carriers. QoS helps with some of the problems as long as you are on your own network, but we all interconnect and we cant control what the far end uses or who our clients call.

So what you are seeing with this one product is just the tip of what is going on in the industry and you will start to see it on what you think are analog trunks too.

I hate to say it but its probably going to get worse before it gets better at this point.

 

[intrigrant]

Here in Belgium all ISDN BRI lines are in the process of being replaced wit IP based BRI lines, if the customer want it or not the BRI lines are converged to BRI over SIP.
In our experience there is hardly a problem with analog modems, there are two major providers here and both work well with analog modems/faxes.
So stating that it cannot be done is not true, it is more like the provider doesn't want to invest in a proper backbone and just want to cash on regular calls.

 

[Signo]

I never said it could not be done. In the US we have so many players in the game over such a large area we have to interact with less then desirable providers at times. Not to offend you but Belgium is roughly the size of the state of Maryland, if I only had to deal with one state and a few providers plus international life would be good. If I can keep traffic on my network I have good modem/fax service, but more often then not my call is being handed off to second party. As you pointed out they just want to cash in and don't really care about the customer. In the US we are loosing our old school people to retirement and are plagued with people who just don't care or are under trained. People that have been doing this for a long time are appalled at how far we have fallen.

I had a customer drop some foreign exchange lines a few weeks ago, simply because Verizon could not figure out how they got to the customer premise. The lines were in place for 25 years and because they couldn't figure out who to dispatch they kept closing the ticket. Customer got tired of fighting and we both lose money.

The bottom dollar at the expense of reliable service is what drives a growing majority of these US providers. This is just what I see happening around me.

 

[intrigrant]

O yes, the country of telecom cowboys, I could have known. Every provider has its own set of protocols which accidently doesn't match anything else but it was cheap you know....
I feel sorry for you but if you get tired of it you can always come overhere, good social laws, good salary, best beer in the world and very nice women too. And nowadays the number two country in the FIFA world soccer ranks.

 

[joe2938]

FIFA Please I can't stop laughing!

 

[intrigrant]

Well, we did have some money left from last years budget so...

 

[Signo]

I was in the Army a long time ago and I love Europe. I envy your training and work ethic. We have lost our way and I dont see us coming back anytime soon.

 

[tlpeter]

Signo, you list of equipment has some which i don't know but most are available with a version that connects by the internet.
Alarm systems do that too and as a backup they use a simcard in case there is no internet.
And the size of the country should not matter, i t could even be much better if there was more to sell


BAZINGA!

I'm not insane, my mother had me tested!

 

[Signo]

Yes most of these devices are able to be connected via the internet, but it creates a burden of cost on the customer. I am not against progress. I was just pointing out why we see some of the problems we see in the US. Not all PBX vendors are affiliated with telco's and some small shops may not completely understand what is happening at the core of our industry.

I was just really a rant about what is happening to before my very eyes.

I didn't mean to hijack the OP's thread.

 

[tlpeter]

Signo, you are right.
I only do not understand why this cannot be covered within a maintenance contract for these devices.
Overhere the smaller shops use a pin terminal which can do wireless transfer between the terminal and my card.
This can only do small amounts of money and with a limit (higher then you will need your pincode)
The bigger shops do not do it as it costs money.
The suppliers should replace them so that they have less issues on older terminals.

BAZINGA!

I'm not insane, my mother had me tested!