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Sonicwall blocking udp ports

Even with the sonicwall allowing all the udp ports but we are having some of the ports just drop packets. This causing phone calls not to come in to the voip system. I have opened what I thought was the correct range but still no luck. I also turned on the voip sip feature in the sonicwall which helped cure some of the issues but we'll still get a few phones that will drop off until it's either reset or finds a different port.

JAN PAKULA

what sonicwall you have?

can you tell me what setting you have here

usually under
Firewall > TCP Settings or Firewall > advanced> TCP Settings

Enforce strict TCP compliance with RFC 793 and RFC 1122 - enabled?

Enable TCP handshake enforcement - enabled?

Enable TCP checksum enforcement – If an invalid TCP checksum is calculated, the packet will be dropped. - that might be why you loosing traffic - make sure this one is disabled

Default TCP Connection Time-out – enabled?

Maximum Segment Lifetime (seconds) -enabled?

https://www.fuzeqna.com/sonicwallkb/ext/kbdetail.aspx?kbid=3768&p=

do you have 2 firewalls - if yes check those settings on both?

also have a look on this one

http://help.mysonicwall.com/sw/eng/305/ui2/23200/VoIP/Settings.htm

and this one

inactivity time-outs on udp or sip might be causing traffic lose:

http://www.informaticapressapochista.com/asterisk/asterisk-with-sonicwall/

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CUHSupport

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JAN PAKULA

well your phones are using sip which is using tcp protocol to establish connection - than it goes to udp - all depends on your set-up.

can you enable heandshake and strict compliance (on both firewalls) - and have a look wireshark whats going on the cable

CUHSupport

ASKER

I enabled them, would that mean perhaps I need to change some ports for tcp? Or do I only need to have UDP open? I'll start taking a look at wireshark with the new settings.

JAN PAKULA

i would open both

CUHSupport

ASKER

I ran some more firewall exceptions but was still getting some packet drops. It seems to drop them off after around 15 minutes on the port. Could that be a setting in the sonicwall?

Mohammed Hamada

CUHSupport,

What SIP server you're using? and how are you publishing ports on the firewall ? Are you using Static NAT ?
Have you set your SIP server's Network default gateway IP to point to the internal IP of the Sonic Firewall?

Could you please make a call and trace it by Wireshark, post your wireshark log here. It might be that the range you have enabled on the firewall is not correct.

CUHSupport

ASKER

Had to increase time for timeouts