VOIP phones and latency issues
Firebox T40 on 12.6.1
A customer has been having choppy voip issues for months. We normally don't configure QOS of any kind and have never really had a need too. They were on a 25/25 MB fiber connection which should be adequate as 90% of the work they do is internet based. We got them to upgrade to a 50/50 and still the same issues. The VOIP carrier is saying the phones are showing 2000ms pings a lot when reaching out to the PBX. When I am onsite I have no issues with pings. Pings from PC's are normal. I have triple checked the ports and verified with them what needs to be open. We have the outgoing policy disabled and only allow ports we specify. I even setup a guaranteed bandwidth traffic management action of 15MB (From ->To) and applied it to the 4 policies I have setup that deal with phone traffic. My understanding of QOS is very little. I have no idea how to set it up or what the options mean. Would it make a difference do you think? What is best practice when using VOIP phones on a watchguard? Personally im leaning toward an ISP issue because my speedtest results vary day to day. Last night 38/38 was all I could get but even that should be enough for 8 or so phones. They told me the phones themselves only reach out on port 5060 to the pbx system and I have a rule allowing Any-Trusted to the DNS hostname of the PBX TCP/UDP 5060. I am at a loss of what else to do on the firewall to potentially figure out the cause. I am probably going there tomorrow to troubleshoot more in person and make some calls while watching traffic to see what I can see. Was just hoping if anyone had any ideas they would share them before I go on site.