Faxes cut off after several pages 2

[wesblevins]

Hello all,

We're having a problems with analog fax machines connected to our IP Office.

Inbound faxes will cut off after a portion of the fax has been delivered. For instance, if the fax was meant to be 8 pages, a fax machine may receive 3 and a half pages. If the fax was meant to be 3 pages, we may get a half of a page.

This happens to all of our fax machines regardless of make or model.

Any advice?

 

[Gibsonic]

what type of CO circuit do you have? analog POTS? PRI? T1?

is the call at any time going over an VoIP trunk?

 

[wesblevins]

Thanks for your reply!

We have 4 PRI lines coming into a central office. Other sites are connected to the central site via T1 lines.

All faxes are connected to analog ports.

The problem happens at all sites, including the central site.

The fax traffic does not travel over VoIP trunks.

 

[wesblevins]

I forgot to mention that the fax cutoff also happens within the agency on site to site faxes.

 

[Gibsonic]

hrm.... what version IPO are you running at your sites?

 

[wesblevins]

3.1 across the board.

 

[aloose]

upgrade to 3.2 I just upgraded last night and oh god is my life easier now! 3.2 rocks. Avoid 4.0 like the plague though till it gets better.

 

[wesblevins]

I certainly don't mind upgrading, but this seems like a pretty specific problem.

I'd like to know what's causing it or at least where to look before I add a different headache.

I appreciate the answer though, and if no one else has any suggestions I may try an upgrade.

 

[Gibsonic]

i deploy 3.1(65) exclusively. very solid 3.1 release. go to this version before 3.2 to see if it is a bug problem.

can you successfully send from faxA to faxB on the same switch?

if it is only when going switch to switch or CO to/from switch then i would think those are trunking issues.

So what type of trunks do you have connecting your different locations if not VoIP? If you do in fact have a VoIP trunk over your P2P T1, then make sure "Fax Transport" is checked and be sure you have enough bandwidth...not to mention all the other variables when using VoIP.

 

[wesblevins]

Ahhh yes, we do use VoIP trunking site to site via the T1s.

I was mistaken about what you were asking originally.

Each of the trunks is set to enable fax transport support. The compression mode is set at g.729(a).

Our utilization across the T1s rarely reaches 30% I've never seen it above 40%

Could the compression mode be an issue?

Also we are running 3.1 (65).

Thanks for all the responses so far!

 

[intrigrant]

Fax support over IP will only work with the G.711 codec.

You can create a separate IP Line for faxes using only the G.711 codec with the same destination IP address as the voice lines only the outgoing LineID must be different ( and no SCN on this line ).
Route all fax numbers over the new IP Trunk to the other site and see what happens.

 

[aarenot]

Lets see the user, and ext settings for the fax machines if it is not fixed yet. exts all settings, user-telephony settings.


You may want to try playing with the analog ext settings, adjusting the hook persistency, (IVR port selection type, and disconnect pulse width). The system, or the fax machines may be seeing a silence, or an interuption of signal for long enough period of time to see it as a disconnect, and hangin up. If you have a analog test set try going off hook after the faxes hook up, and staying off hook to ensure there is an open line. If you are on the recieve end, and the recieve fax hangs up but the fax continues to come you can tell, and know the fax machine is hanging up on the call.

Play a little you have a few items in the mix, fax1, PRI, IPO, possibly T1/IPO, fax2. Try to determine which unit disconnects first.

Another suggestion:
Get a fax finder fax server, and send all the faxes via DID, through the IPO, to a fax finder server to attach and send via Email. The cost would probably be about the same as replacing all your stand alone fax machines if you have nice afx machines. It would also allow faxing from the desktop as well.

 

[telcotechavaya]

I had dramas with faxes cutting off, and this followed an upgrade on a 403 DS to V3.2.55 from 2.1.27 via the normal step process for 403.
I downgraded back to 3.1.65 and faxes were sweet after that.
The faxes came out all distorted though, not cut off necessarily.
We've experienced the IP trunk drama with Faxes too. 2 or 3 pages of 8 would work sweet. I wasn't aware of the G711 req.
Live and learn i guess. We just setup faxes to go out on PSTN.
Easy. always works. cost of our labour to fix, and cost of not having faxes working.....

Cheers,

Chris

 

[PlatinumGuy]

Have a look in the IPO maint manual as there is a section concerning this.

I think the bottom line is that there is a problem with the network clock that you are synching to.

Clock quality issues cause exactly this type of fault.

On a site that had this issue pretty bad we temporarily set the clock quality to unsuitable and the issue dissapeared thus proving when the IPO synchs to the network clock there is slippage.

Try running an isdn trace, do you see any falc packets? This also indicates poor clock quality.

ACA - IP Office Implement
ACS - IP Office Implement
ACE - IP Office Implement

 

[wesblevins]

I think it's fixed!

G711 seemed to be the ticket. I used this compression method for one site at a time over a couple of days and watched the problem disappear with the changes.

Thanks for all the help!