[Freeswitch-users] Firewall mysteriously starts blocking calls to port 5060
chad at apartmentlines.com
Sat May 4 15:36:22 UTC 2019
It wasn't a fail2ban issue...
This particular provider says they only send SIP traffic over UDP, and I
had only opened TCP traffic to port 5060 in my firewall.
The part I don't understand is how I was able to receive any calls at all
from them without UDP/5060 open -- it worked for hours with my new firewall
config up. That's just weird...
Also, can anybody explain why a provider would use UDP for SIP traffic?
>From my brief reading of the spec, it does seem to be a valid protocol to
use, but UDP's fire and forget approach seems a poor choice for this task.
On Fri, May 3, 2019 at 11:56 AM David Villasmil <
david.villasmil.work at gmail.com> wrote:
> I'd say this is a question for shorewall. But since you're here, is there
> maybe some flood-prevention mechanism that would block it? Did you check
> shorewall's log to try and find the reason it was blocked?
> David Villasmil
> email: david.villasmil.work at gmail.com
> phone: +34669448337
> On Fri, May 3, 2019 at 6:07 PM Chad Phillips <chad at apartmentlines.com>
>> Recently I reconfigured my firewall (via Shorewall) to block all inbound
>> traffic to port 5060, except for whitelisted IP addresses from my inbound
>> DID providers. After setup, we ran tests and everything worked fine for all
>> incoming calls across all providers.
>> Then a few hours later, calls from one of our providers started being
>> blocked. All calls from our other providers continued coming through fine.
>> Upon restarting our firewall service, the blocked calls from the single
>> provider started coming through again.
>> Between our successful tests and the start of the issue, there were zero
>> changes made to the server.
>> So why would my firewall suddenly start blocking inbound traffic from a
>> whitelisted IP that it was previously letting through??
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>> Enhance your FreeSWITCH install with disruptive priced SMS and PSTN
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> The FreeSWITCH project is sponsored by SignalWire https://signalwire.com
> Enhance your FreeSWITCH install with disruptive priced SMS and PSTN
> Build your next product on our scalable cloud platform.
> Join our online community to chat in real time
> Professional FreeSWITCH Services
> sales at freeswitch.com
> Official FreeSWITCH Sites
> FreeSWITCH-users mailing list
> FreeSWITCH-users at lists.freeswitch.org
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