Fax over IP with 3300 ICP

[jneiberger]

We're considering using Mitel for VoIP and one key issue is faxing. We will have a lot of site-to-site faxing over the IP network. Our plan was to connect our fax machines to the ONS ports on the 3300. Does this sound feasible? Have any of you had any problems with faxing over IP with 3300s?

Thanks,
John

 

[MitelInMyBlood]

Fax works good mitel to mitel over full bandwidth uncompressed G.711 routes with 802.1p/q QOS . I honestly have not tried it over G.729 compression or without voice priority. As long as you're going over your own private LAN/WAN and use a dedicated voice VLAN for voip calls your faxes should be fine. I don't know what speed is supported, but on an uncompressed IP route I would think at least 9600 baud and maybe even 14.4 Just a guess compression would clamp fax speeds to 2400 or less. Compression is intended for voice. Fax tones are not voice

 

[jneiberger]

We received two demo 3300s today and did some fax testing (g711) with the help of the reseller. We were faxing from a site with a T1 to a site with a DS3, and both ends have QoS configured. We didn't have spectacular results. In fact, roughly half of the fax attempts failed and we weren't able to determine why.

 

[MitelInMyBlood]

Have your lan guy put a sniffer on your network and find out whats happening.
I know of a site where they fax from a SX2000 over MSDN T1 to an early vintage 100-user 3300 in the same room, then IP over DS3 to another 3300 600 miles away then from there to an MSDN t1 to another SX2000 to another fax, 4 switches in all, tdm to ip, ip to ip, ip to tdm.
They don't have any analog ASU ports on either of their 3300s, they are early units (pre MX) and their 3300s are only used for IP trunking but still the E2T is doing the conversion at both ends (same as it would be with an ASU).
I do know both fax machines are same models, some Jap brand which might have some bearing on this.
They consistently achieve 9600 speed faxing over a distance of 600 miles.
They can't do 14.4 but they never had consistent 14.4 success anyway.
Both 3300s are running release 5 software.

 

[jneiberger]

It turns out that one of the 3300s was connected to a port set to 10/half. I moved it to a port set for 100/Full and faxing worked just fine.

Thanks!

 

[MitelInMyBlood]

that would probably do it.

Its also amazing how many people are knowledge impaired about using hubs with voip.

I had 200ICP client with a 5310 VOIP conference phone.
He needed to have some people come in to the meeting room that wanted to hook up their laptops.
Not having a spare network port on the conf. table he has a brain fart and unplugs the phone then connects it back via an 8 port 10BaseT hub with 6 laptops connected too.
Everyones trying to follow a powerpoint presentation.
Then he complains about how crappy the voice call was.
This was on a 200ICP without the 2nd port on the phone enabled.

I never figured out why anyone would buy a VOIP phone system but not buy the option to have the 2nd port on the phone enabled.