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Callcentric issues

Started by Judgeless, October 25, 2012, 12:01:03 PM

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Judgeless

I have been using Callcentric for about 9 months on two different OBI110's. It has worked perfect. Recently they have been having issues with denial of service attacks.  They also are having DNS issues.

Both my phone lines have been dead for a week.  I opened a service request asking if everyone is down and they never respond.  It seems like they are no longer supporting customers just billing them.

Are other people having this issue?  Here is the error I get on both boxes.



Can someone recommend another provider in the US that I can move my number to?



A_Friend

There are some newish configuration instructions for the OBihai boxes on their customer portal.  Just log in there and it's on the front page.  You should be able to get things working again.  My OBi100 box is quite functional on CC at the moment.

Callcentric's troubles seemed to be confined mostly to their SIP interface.  Their back-office stuff is still working, including their DID handling.  If you can't get your SIP account with them functioning, you can go into Preferences/DID Forwarding and send the DIDs to any number or URI.  Bear in mind you'll have to pay outgoing rates to send it to another non-CC DID, but URIs anywhere are free, as are iNums.

What I did for two of my CC DIDs, when CC was blown out, was set up subaccounts on one voip.ms account and forwarded each DID to a voip.ms subaccount URI.  The subaccount feature of voip.ms is one I find quite interesting.  I don't know what the limit is, but you can have multiple ones and not only can you register each one on a separate ATA SIP channel, you can assign an internal 3 or 4-digit extension number to each one, and address each one as a separate URI from outside.

The DID Forwarding was working well for me when everyone else was complaining they couldn't even make Call Treatments work.

If you do get your free voip.ms account, be aware that it might not do very much until you deposit $25 into the account.  It won't even dial toll-free numbers on their value routing plan, which are free, and I seem to remember they wouldn't even let me dial through SIP Broker at the time.

Voip.ms is quite a different system than Callcentric.  I think they each have great features and I'm keeping both of them, which will be especially important if/when Google Voice decides it's not a free service anymore. 

VOIPisGreat

For voip.ms, do you need to have a DID to be able to receive call thru SIP URI? If not what does the URI address look like?

Judgeless

I have all the settings exactly like their web site shows.

Service Providers > ITSP Profile > SIP
ProxyServer = callcentric.com
RegistrarServer = callcentric.com
UserAgentDomain = callcentric.com
OutboundProxy = callcentric.com OR srv.callcentric.com (You can use either server, please test and configure this setting accordingly)
X_ProxyServerRedundancy = Checked

Here is how it looks.



and farter down I have the X_ProxyServerRedundancy = Checked

I still get this everytime



This is on both OBI boxes that have worked for a long time.

ProfTech

My 110 was crashing yesterday afternoon also. Try setting
X_ProxyServerRedundancy back to default by checking the "Default" box and
make sure X_DnsSrvAutoPrefix is Checked.

Click "Submit" and reboot. You should be able to leave everything else alone.

VOIPisGreat

What do X_ProxyServerRedundancy and X_DnsSrvAutoPrefix do?

Sorry about the novice question, I want to understand as I have X_ProxyServerRedundancy checked and X_DnsSrvAutoPrefix blank and my obi is working fine.

Judgeless

I got it working.  There are having major DNS issues and they want you to force all devices like the Obi box to use their DNS servers and not your ISP.

I don't get it.  If they would have mentioned this on their web site I would have fixed the issue and moved on. 

user834

Quote from: Judgeless on October 26, 2012, 03:06:47 PM
I got it working.  There are having major DNS issues and they want you to force all devices like the Obi box to use their DNS servers and not your ISP.

I don't get it.  If they would have mentioned this on their web site I would have fixed the issue and moved on. 

No.  CallCentric is NOT having major DNS issues.  USERS of CallCentric services and some ATA devices are having major DNS issues after reconfiguring to use CallCentric's suggested setup to fend off the massive attack they're under.

In the beginning, like everyone else, CallCentric was using regular "A" records for DNS resolution to their proxy servers for registration.  A DNS query by the USER'S device is a UDP packet and expects a UDP response because the overhead is low.  The response contains one or two IP addresses of the proxy servers and the registration begins using those.  Then came the huge denial of service attack that swamped their proxy servers. 

CallCentric added memory and resources to their proxy servers, but it wasn't enough to fend off the attack.  So, they started adding proxy servers.  I think they're up to 20 or more by now.  The also set up new DNS SRV type records to return a randomized list of the entire pool of servers.  That will balance the load over the entire set of servers and they can continue to add servers as necessary to thwart the attack.  They asked their users to reconfigure their SIP and ATA devices to request the new SRV type DNS records.  (They continue to support the "A" record DNS queries, but those servers have little defense against the attack and are prone to overloading.)

Whereas the old "A" record DNS query responses were quite small, the new SRV responses are much larger because of the number of servers CallCentric has configured into the server pool.  The new SRV response is too large to fit in a UDP packet.  By protocol standards, when that happens, the DNS is supposed to mark the UDP response truncated.  It isn't defined whether a partial list of servers (whatever will fit) is to be returned in the UDP response or not.  Some DNS servers include the partial response and some don't.  The popular Google  and OpenDNS servers do not.  Most ISP provider DNS servers appear the include them. 

What should happen is the device (i.e. OBI) sees the truncated flag and re-queries the DNS using TCP, which allows for a larger, multi-packet response.  Unfortunately, most devices seem not have implemented this part of the DNS protocol.  So, they are relying on the partial list of servers supplied in the truncated UDP response sent by some DNS servers.  CallCentric even provided the addresses of a couple of DNS servers they knew to "work" by supplying the truncated list.

Using the truncated partial list of proxy servers is much better than using the "A" record servers from a stability point of view, but not without problems.  SIP devices re-register periodically.  If the new partial list of randomly ordered servers doesn't include the currently registered server, the device will drop the registration and register on one of the new IP addresses.  That leaves a small window with the device unregistered and no calls.  I've heard that some devices are dumb enough to actually drop a call in progress when this happens, but I haven't seen it to know for sure. 

So, the bottom line is CallCentric is adding servers in parallel with each other to fend off an attack.  They have asked their users to use SRV type DNS requests to automatically load balance across the new set of servers.  Different DNS servers behave differently when sending truncated UDP responses and many (most?) SIP and ATA devices don't properly implement TCP DNS queries in response to receiving a truncated UDP response.

QBZappy

user834,

Thanks for the explanation. Can you give some advice on which direction obihai should be taking in order to improve their devices in order to implement what seems to be a reasonable response to a DDOS attack. We may see other voip services implementing the CC strategy.
Owner of the 1st OBi110/100 units in service in Canada & South America. 1st OBi202 on my street. 1st OBi1032 in Montreal.

Judgeless

Thanks for the explanation.  I wish Callcentric would have been more pro active in informing their customers on what was going on and how to fix it in a simple paragraph.    Instead I wasted a lot of time trying to fix something that worked fine for 9 months.

hwittenb

Quote from: VOIPisGreat on October 25, 2012, 12:37:29 PM
For voip.ms, do you need to have a DID to be able to receive call thru SIP URI? If not what does the URI address look like?
VOIPisGreat,

You can call your voip.ms sub-account phone with the following sip uri format.
nnnnnnx@servername.voip.ms
where nnnnnn is your voip master account number, x is your voip.ms sub-account number and servername is the voip.ms server where you have your adapter registered.  Actually your proper sip uri is shown on the "Manage Sub Accounts" web page when you move your cursor over circle i next to your sub account extension number.

When I try a test call using this sip uri it works when used as a forwarding number at IPKall.  You cannot "manage" this incoming sip uri as you would a regular voip.ms DID where you forward it at the voip.ms account level, route to ring group, etc.

If you wish to setup a regular incoming DID as a sip uri, voip.ms has an option for that also.  They call it a Virtual DID.  The advantage here is that you can manage the sip uri like a regular DID.  Voip.ms has a fee for this option, currently 25 cents per month with a per minute incoming call charge of one tenth of a cent per minute.

Ostracus

User834 great explanation. Unfortunately I bet the Obihais aren't the only one with this problem. I wonder if a DNS proxy between the two would remedy the situation?

Johnny

While I'm sure user834's response was a great response, could someone translate that response into plain language for us technically challenged types?

I have an OBI 110 and I had CC set up on SP2 until the rebooting problems started and then I deleted it and the rebooting stopped.

Other than porting my number out of CC, is there a way to get CC working with the OBI 110 without all the rebooting issues?  Something simple hopefully.

Can a number from CC be ported to Google Voice?

Again, thank you user834 for that lengthy explanation, I just wish I understood it.

Thanks

tome

Quote from: Johnny on October 28, 2012, 06:54:36 AM
While I'm sure user834's response was a great response, could someone translate that response into plain language for us technically challenged types?

I have an OBI 110 and I had CC set up on SP2 until the rebooting problems started and then I deleted it and the rebooting stopped.

Other than porting my number out of CC, is there a way to get CC working with the OBI 110 without all the rebooting issues?  Something simple hopefully.

Can a number from CC be ported to Google Voice?

Again, thank you user834 for that lengthy explanation, I just wish I understood it.

Thanks

In a nutshell Obi needs to fix the bug they have which causes the box to reboot every time they get a truncated dns response or in processing SRV records, whatever it is. 
Tom

Johnny

Quote from: tome on October 28, 2012, 08:55:53 AM
Quote from: Johnny on October 28, 2012, 06:54:36 AM
While I'm sure user834's response was a great response, could someone translate that response into plain language for us technically challenged types?

I have an OBI 110 and I had CC set up on SP2 until the rebooting problems started and then I deleted it and the rebooting stopped.

Other than porting my number out of CC, is there a way to get CC working with the OBI 110 without all the rebooting issues?  Something simple hopefully.

Can a number from CC be ported to Google Voice?

Again, thank you user834 for that lengthy explanation, I just wish I understood it.

Thanks

In a nutshell Obi needs to fix the bug they have which causes the box to reboot every time they get a truncated dns response or in processing SRV records, whatever it is. 
Tom


Thanks Tom.

Any idea if the OBI team is working on this fix?  Maybe a new firmware upgrade soon?

I really liked CC, but it just doesn't work anymore with my OBI and I'm not buying another ata.

So, if OBI doesn't come up with a fix for this bug I will probably port my CC number to Voip.ms.

Do you know if CC is working with OBI to come up with this fix?  Hopefully they are.

Thanks again..

tome

#15
Quote from: Johnny on October 28, 2012, 09:23:35 AM
Thanks Tom.

Any idea if the OBI team is working on this fix?  Maybe a new firmware upgrade soon?

I really liked CC, but it just doesn't work anymore with my OBI and I'm not buying another ata.

So, if OBI doesn't come up with a fix for this bug I will probably port my CC number to Voip.ms.

Do you know if CC is working with OBI to come up with this fix?  Hopefully they are.

Thanks again..

Obihai has a history of not saying anything about bugs, what is being fixed, when/if new firmware is coming, or what new features they might implement. Heck, even after new firmware is released they often don't give the whole (or any!) indication of what was fixed.   When it works, it works, when it doesn't, who knows.  You pay your money, you take your chances.  

Had I known exactly how uncommunicative they are I wouldn't have bought the box in the first place and I definitely don't recommend it to anyone these days.  When I first bought it there was a forum member (RonR) who singlehandedly made up for Obi's poor customer service.  When RonR left (kicked out?) so went any hope at all for a good long term user experience.

Tom

ps:  Ohihai doesn't need to work WITH CC.  They need to fix their implementation of standard protocols.

Johnny

Tom,

Thanks for all the helpful info.

At this point I'm strictly using the OBI 110 with one of my Google Voice accounts and nothing else.

I'd like to have another VOIP account to be able to utilize 911 services.

So, I guess I will wait a short time and if no resolution of the rebooting problems, I will probably port out of CC and hope the next VOIP provider doesn't have these same issues with the OBI 110. 

Thanks again  for your help.  Appreciate it.

P.S.  I remember RonR quite well.  He actually helped me out on these forums too. 

carl

Amazingly, I have no ,problems with 202 reboots or anything else and Callcentric works again as it is supposed to.
The only thing I had to do was to change the digitmap because the pro configured one from Obi was not good but that had nothing to do with current CC problems.
Yeah, many of us miss RonR.

rsriram22

i deleted CC from my SPx on my obi100 and world is back to normal again... i dont think obi is going to 'fix' anything as nothing 'broke' from their standpoint, i guess..

i will wait for couple of days and just take my number from CC to elsewhere, if things are still awful. (frequent reboot thing just annoys me)..

right now am without e911 support as i am fwd'ing all my calls from CC to my obi via SIP URI forwarding..
have two 100s and one 110

QBZappy

Quote from: rsriram22 on October 28, 2012, 06:44:52 PM
i am fwd'ing all my calls from CC to my obi via SIP URI forwarding..

rsriram22,
Can you show us some examples oy your sip uri forwarding.
Owner of the 1st OBi110/100 units in service in Canada & South America. 1st OBi202 on my street. 1st OBi1032 in Montreal.