 bbbc
join:2001-10-02
NorthAmerica |
bbbc
Member
2011-Nov-5 6:54 pm
[Callcentric] LNP fax number for fax reception feature?I've gotten mixed signals from reading the various threads on faxing with Callcentric. It looks like the best solution for my situation would be their fax reception feature, » www.callcentric.com/feat ··· eception . I probably will never need to send an outgoing fax with T.38, but I want a place to port a fax number / DID to. I also don't plan on receiving anything, except for once in a blue moon. The LNP porting faq states, " Please do not port-in numbers you plan to use for fax reception. Due to unreliable fax reception in some circumstances we do not recommend porting-in phone numbers you plan to use for fax reception." Further doom can be read at » www.callcentric.com/feat ··· eception , " Please note: The fax reception feature is currently offered as an option on all Callcentric accounts; but is currently un-supported as we work to improve the reliability of fax reception under certain conditions." I just want a cheap solution to have a non-essential fax number. The next option would be UnityFax, » www.unityfax.com , but they got a really crappy review, » www.yelp.com/biz/unityfa ··· ut-creek , and $5 is too much for what I need. I know the disclaimers are to save the heartache for the user and the company (Callcentric), but I'd rather pay $2 to park / port a number where the incoming fax reception will work most of the time. |
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Please note, this is just my personal opinion as a CallCentric customer. Also take my opinion FWIW as I am not a "tech" person.
I think that they are being a bit cautious (as always).
I think that you won't have any problems:
a) If you are in a Tier A area of the US or Canada.
b) If they are able to port your number.
c) If the people sending you faxes are from the US or Canada.
d) If no "call forwards" are done at either end.
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I use the CallCentric fax reception feature on a daily basis at my business. We receive many multi-page faxes with no problem.
However, the number in question is one obtained from CC, not a ported number....
Even so, I think you'll be ok. I really do.
You'd never lose the number. You could always port back out, in the unlikely event of a bundt cake mishap.
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You mentioned Unity Fax. I see they charge $ 15 for the port but then charge an extra $ 1 a month [forever!] for a ported number.
CallCentric charges $ 25 for a port but there are no penalty fees after that.
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I'm really happy with the service because faxes are sent BOTH to email and on their website (my choice). If I accidentally lose one copy of the fax, I can get the other. |
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MangoUse DMZ and you get a kick in the dick.
Premium Member
join:2008-12-25
www.toao.net |
Mango to bbbc
Premium Member
2011-Nov-5 10:26 pm
to bbbc
Given your needs, Callcentric should work just fine. I have a suspicion that the warning about porting in numbers is there for political reasons rather than technical issues. There's no technical reason a ported number should perform any differently than any other number*. However, in the event that the fax reception feature doesn't perform as expected, they (understandably) don't want the user to be upset, and make a scene demanding a refund of their porting fee.
Callcentric did upgrade their fax reception feature some time ago. It now supports ECM and generally works a great deal better than the time when the disclaimers were written. However, the disclaimers have not been removed.
m.
*With the exception of a VoIP provider that uses a carrier only for ports that doesn't support fax, but my guess is that this is not the case. |
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to bbbc
Here are some older comments by the fellow who is associated with CallCentric: ....Regarding Callcentric - I'm quite sure about how the DIDs are delivered to us ) Being a telecommunications carrier - we either use SS7/TDM hand-off or get the DIDs via dedicated inter-switch links (from those carriers whom we peer directly with) or via SIP from foreign international carrier whom we get over 40 countries DIDs from. Just for this conversation sake - the toll-free DID numbers are delivered to us via SS7/TDM therefore our e-faxing solution for calls arriving to our own toll-free DIDs is 100% guaranteed. Fax calls to most of US/Canadian DIDs on our network would also be delivered problem-free with exception of few tier-2 carriers who provide us with rural/otherwise hard reachable DIDs and who uses outdated equipment or less than qualified engineering personnel (unfortunately, I must admit - there are still many such carriers who live on FCC's "donations" and who provides less than adequate service for the money we pay).
A totally different animal is delivering faxes coming to our international DIDs and/or from those customers who forwarded FAX calls to us from their own DIDs whose calls already have been delivered (by their providers) via multiple VOIP legs. In case of international DIDs - it all depends on bandwidth/jitter available to the carrier whose DID is used in a call and/or on whether the T.38 is supported or not. In a case when some "smart" users forwarded to us calls they received from their 3rd party DIDs - the probability of such a FAX call being properly completed is approaching zero... Unfortunately, such users are usually most loud about "quality" of fax termination because they do not really understand how the fax transmission works.
I must explicitly admit that a fax transmission from IPKall DIDs sent to CC e-fax termination (or to that sake - any 3rd party DIDs from F9, VOIP.MS, DIDWW, etc.) will almost always fail because of multiple, long VOIP paths involved (each path adds its jitter, latency and possible packet loss) while strict timing required to fax protocols to work properly will [obviously] be violated. Do not forget - at both ends of such a "fax" transmission still are connected just usual, plain fax machines who have no idea of underlying SIP or even T.38 protocols, but who is very strict about timing and appropriate bit-strings receiving.... I agree with Mango's comment (and with my own of course as long as the four points a|b|c|d are fulfilled). |
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I wonder why forwarding did's to Callcentric's fax termination fail, yet I've used Ipkall in the past to receive faxes to my machine and it worked wonderfully at the time. Well, I have a very low jitter internet connection, and as long as the underlying networks are low jitter it should work regardless of how many forwards. |
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said by jason_m:I wonder why forwarding did's to Callcentric's fax termination fail, yet I've used Ipkall in the past to receive faxes to my machine and it worked wonderfully at the time.
They mainly fail if coming from substandard and/or overseas connections. said by jason_m:And as long as the underlying networks are low jitter it should work regardless of how many forwards.
Not really. Something is lost in each handoff, and in addition, the more carriers are involved the more chance of a substandard one. |
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said by PX Eliezer704:said by jason_m:And as long as the underlying networks are low jitter it should work regardless of how many forwards.
Not really. Something is lost in each handoff, and in addition, the more carriers are involved the more chance of a substandard one. I guess the general consensus with faxing over voip is that the audio and connection have to be perfect. Not the case. Fax can survive a certain amount of audio loss. Even if a little something is lost, that isn't necessarily a bad thing. Like Callcentric's "strict timing" etc. comments, it just isn't that strict. Things of that nature are v.34/v.90/v.92. Not 9600/14400 faxes - they are sub v.34, those were made at a time where there were plenty of mushy analog trunks in operation. A great deal of these complaints are usually the customer's internet connection is already close to the limit so that any additional losses from a forwarded call will cause it to fail. They will often disable ECM mode, which makes it appear to work until they try to forward the calls. Unknown to them all along pages are blank, missing, or cut in the middle. Of course there are sub standard carriers out there, probably isn't that bad for domestic calls. I don't like to believe that if forwarding a call once will hit a bad carrier as frequently as it is purported. |
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You raise good points. You spoke of forwarding a call once. AFAIK the problem for CC had been multiple handoffs, especially from overseas. I did my own little study last year. People sending me faxes--->CallCentric DID--->CallCentric Fax Server:
Close to 100 percent reliable. . People sending me faxes--->OptimumVoice line optimized for fax--->CallCentric DID--->CallCentric Fax Server:
About 75 percent reliable (apparently due to the forwarding). |
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bbbc
join:2001-10-02
NorthAmerica |
bbbc
Member
2011-Nov-6 1:16 am
It looks like Anveo offers the same fax service, but I see their DID selection (rate centers for porting) is really limited compared to Callcentric. I'm assuming VoIP.ms and Callcentric use Level 3. |
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to PX Eliezer704
said by PX Eliezer704:You raise good points.
You spoke of forwarding a call once. AFAIK the problem for CC had been multiple handoffs, especially from overseas.
I did my own little study last year. People sending me faxes--->CallCentric DID--->CallCentric Fax Server:
Close to 100 percent reliable. . People sending me faxes--->OptimumVoice line optimized for fax--->CallCentric DID--->CallCentric Fax Server:
About 75 percent reliable (apparently due to the forwarding). If 75% is achieved with an optimized OptimumVoice line forwarded, then I would question what OptimumVoice does to the line? My gist is that if all of the connections along the route are low enough jitter and other audio defects, then that number should have been at least in the 90's. About 75 is just too low for a line that is advertised as being optimized for fax, whatever that is. I can achieve better than than that with normal lines, dids, a pap2, and a fax/all in one machine.  |
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 TrevAcroVoice & DryVoIP Official Rep
Premium Member
join:2009-06-29
Victoria, BC
1 recommendation |
to jason_m
said by jason_m:Fax can survive a certain amount of audio loss. Even if a little something is lost, that isn't necessarily a bad thing. Like Callcentric's "strict timing" etc. comments, it just isn't that strict. Things of that nature are v.34/v.90/v.92. Not 9600/14400 faxes - they are sub v.34, those were made at a time where there were plenty of mushy analog trunks in operation. Timing is huge, and is a major concern when processing fax data streams. Line noise is more tolerable as fax machies have had to put up with this since their first deployment. Assuming timing is solved (this means your jitter buffer does NOT dynamically grow!) and any T1 connections are properly synced as to not miss any bits, the next concern is ensuring there is no compession of the audio stream. The lossy compression codecs out there, such as G.729, may sound great for speech, but they drop parts of the spectrum that fax machines rely on. |
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hardly
Premium Member
join:2004-02-10
USA |
hardly
Premium Member
2011-Nov-6 4:26 pm
Trev Are the settings given at: » Re: Faxing over Call Centric with T.38, settings, Mango?still relevant, or have they changed? |
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TrevAcroVoice & DryVoIP Official Rep
Premium Member
join:2009-06-29
Victoria, BC |
Trev
Premium Member
2011-Nov-6 5:29 pm
Those are an except of the settings I use for setting up SPA2102 devices that will be used for faxes and I haven't changed anything since posting that, but please let me be absolutely clear I have nothing to do with Call Centric nor have I ever used their service. |
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hardly
Premium Member
join:2004-02-10
USA |
hardly
Premium Member
2011-Nov-6 5:58 pm
Thank you. |
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to hardly
Funny, b/c I use exact opposite settings,  echo cancel on, jitter buffer Low, up and down etc. The jitter buffer setting shouldn't effect fax sending, as it only effects the receive audio. The sip proxy that sends back the audio from the pstn will have a jitter buffer that you have no control of. I actually have very low jitter on my connection, so the buffers at either end probably never grow. Any audio gap or glitch big enough to interrupts the data flow, ECM mode will often recover. The echo cancelers at the opposite end on a pots line if your faxing to a pots line, again you would have no control of the pots echo cancelers. I tend to leave my local echo cancelers on for faxing as it is half duplex and each end uses the same frequencies. I have found sometimes bits of audio echoing back in between the page data, or when they are syncing at the low bit rate can cause it to fail reading that low bitrate data. |
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jason_m
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to Trev
said by Trev:said by jason_m:Fax can survive a certain amount of audio loss. Even if a little something is lost, that isn't necessarily a bad thing. Like Callcentric's "strict timing" etc. comments, it just isn't that strict. Things of that nature are v.34/v.90/v.92. Not 9600/14400 faxes - they are sub v.34, those were made at a time where there were plenty of mushy analog trunks in operation. Timing is huge, and is a major concern when processing fax data streams. Line noise is more tolerable as fax machies have had to put up with this since their first deployment. Assuming timing is solved (this means your jitter buffer does NOT dynamically grow!) and any T1 connections are properly synced as to not miss any bits, the next concern is ensuring there is no compession of the audio stream. The lossy compression codecs out there, such as G.729, may sound great for speech, but they drop parts of the spectrum that fax machines rely on. Timing isn't all that strict in a sense that most seem to think that modems, or fax doesn't have any sort or error correction or recovery. ECM is one of them, at software level. Yes you loose carrier sense if there's a big enough audio problem that the fax/modem's forward error correction couldn't compensate for, but ECM will resend that data past the audio problem. Otherwise frequent audio issues could cause ECM mode to re-try over and over again and never finish. But then without ECM that would surely cause pages to go missing, blank, or cut in the middle. |
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echo cancel on, jitter buffer Low, up and down etc.