Logicwrath Posted January 26, 2017 Report Posted January 26, 2017 We are seeing some issues with a large ring group. The end user would like 15 phones to ring for incoming calls. Should we expect issues with adding 15 phones to a ring group? We are getting reports of issues where the not all of the phones are ringing. I suspect part of it might be due to some delay or weirdness with the current call forwarding. I increased the ring time from 20 seconds to 30 seconds for now to see if that helps.Are their any known issues with having 15 phones in a ring group? I can understand a small call setup delay + a call forwarding delay causing some issues. However, once the numbers port tomorrow I will need to make sure that all phones ring when a call comes in.
Mads Mortensen Posted January 26, 2017 Report Posted January 26, 2017 Hi;I just checked out system (we are using Kazoo CE) -We have a customer with 22 phones in one of their ringgroups - They have no problems
Baze Posted January 26, 2017 Report Posted January 26, 2017 May be worthwhile to check on the networking side also. #1, do they have the bandwidth, because that is essentially 15 concurrent calls coming through, and #2, is their firewall set to bypass any type of flood control rules or otherwise that may be causing problems. Our next step would be to pcap their router to figure out whether the invites aren't getting to their location, or they are, but they aren't then being passed to the phones.
Logicwrath Posted January 26, 2017 Author Report Posted January 26, 2017 This is all good advice. Thank you!
Karl Stallknecht Posted January 27, 2017 Report Posted January 27, 2017 We have a customer with about 25 phones all in a ring group, and they've never reported any issues. Our other customers (even with the same number or more devices) don't have all of them in a single ring group, so I only have one example to go off of.What we often see when a customer complains about some phones not ringing in the ring group are a firewall acting up. Look in the call logs and see if some of the legs say "Recovery on timer expire" - this is *usually* a problem with the customer's firewall. Sometimes it needs a reboot, other times it is too restrictive and needs to be replaced with something else.
Karl Stallknecht Posted January 27, 2017 Report Posted January 27, 2017 FYI 15 phones ringing is not 15 concurrent calls. It's not even 1 concurrent call. An incoming call is just sending tiny packets to the phone to tell it to play a ringing sound. When the customer picks up, then the actual call begins and uses up a larger portion of bandwidth.
Administrators Darren Schreiber Posted February 19, 2017 Administrators Report Posted February 19, 2017 Our very first customer in NYC is still with us. They have 32 phones on a ring group when you call the main number. It was hell on earth to get that working in 2008 hehe - the bridge string in FreeSWITCH was HUGE because there were different settings on each phone. But we eventually figured it out.Since then, it's worked pretty flawlessly. And a lot of other people do it, too.Of course, I think 50 is probably the largest group I know of. If you put 100 or 200 in a group we'll probably hit some new problem we haven't seen before.Sooo I'd call 50 the max I know of :-) but larger might work OK too.
Karl Stallknecht Posted February 19, 2017 Report Posted February 19, 2017 Oh, wait...having more phones in a ring group can cause problems? What exactly is the reason? I'm curious now!
Administrators Darren Schreiber Posted February 19, 2017 Administrators Report Posted February 19, 2017 There are limits in any system on packet sizes and memory buffers. Engineers sometimes code things assuming they'll only ever get so big.Sometimes they'll pick a number like 1024 for the number of bytes that can exist in a string.Well, if you call a phone in our system, potentially it creates this string:bridge {caller_id=X,caller_id_name=Y}sofia/profile/sipint...;some_setting=a&some_setting=bOK, that's for one person. Now you have two people, well, it doubles in length:bridge {caller_id=X,caller_id_name=Y}sofia/profile/sipint...;some_setting=a&some_setting=b,{caller_id=X,caller_id_name=Y}sofia/profile/sipint...;some_setting=a&some_setting=bWell, when you get to 100, maybe you now exceed 1024 characters and something breaks.It's impossible to unravel every single line of code an engineer has ever written to see if they have made an assumption like this basically, hence why they become "bugs" :-) It's something an engineer never thought someone would do, but then someone does it.
Karl Stallknecht Posted February 19, 2017 Report Posted February 19, 2017 Ah okay, very interesting, thanks! :-)
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