[VoiceOps] "...but it works with Packet8"

Jim Gurol jim at californiatelecom.com
Sat Aug 21 14:37:19 EDT 2010

Are you running with an SBC?

Darren Schreiber <d at d-man.org> wrote:

>So do how do we get to where we "don't tweak"? Again, as Packet8 being the reference point, they seem to run into this problem very infrequently now from what I can tell...
>- Darren
>On Aug 21, 2010, at 11:16 AM, Jim Gurol wrote:
>I had a similar issues when moving customers from one platform to another.
>One had an SBC, one didn't. The one with SBC controller handled these NAT
>problems without any tweaks, while the one without the SBC, sometimes needed
>tweaking on customer CPE.
>Jim Gurol
>California Telecom
>-----Original Message-----
>From: voiceops-bounces at voiceops.org [mailto:voiceops-bounces at voiceops.org]
>On Behalf Of Darren Schreiber
>Sent: Saturday, August 21, 2010 10:15 AM
>To: VoiceOps at voiceops.org
>Subject: [VoiceOps] "...but it works with Packet8"
>Hi folks,
>We provide a fully redundant VoIP service to our customers where
>they hook up two cheap Internet connections to our special little box and we
>load-balance / failover across them. We have been running into periodic
>issues with SIP ALG and such typical VoIP crippling technologies when
>hooking up our equipment, requiring us to get into the client's router and
>turn off SIP ALG (or Cisco "fix-up" features). Specifically we have issues
>with 2Wire devices, which are very very popular. We've been assuming this is
>standard/par-for-the-course behavior.
>We have a partner who is reselling our service and he has asked me
>a few times why our service requires any tweaks at all. He is literally
>replacing Packet8 phones with our service. We are utilizing the old Packet8
>phones so it is not a model and unlikely a firmware issue. Something we are
>doing in our way of configuring these phones is fundamentally different then
>Packet8. The reseller feels we should not have to mess with the clients
>router. I'm starting to think he has a valid point.
>So, my question is, why does Packet8 work so well behind so many
>firewalls? I don't think their Aastra firmware is all that different then
>stock Aastra firmware. So my thoughts are:
>- They might be using TCP signaling for SIP call setup instead of UDP?
>- They might be ignoring the contents of SIP packets and rewrites and using
>rather "aggressive" settings on the switch side to figure out routing based
>solely on network headers (we use the actual SIP packets)
>- They force rport?
>I'm just guessing at this point, but the reseller has a valid point
>- we should be able to compete with this directly.
>Let me know your thoughts or if you have any advice on
>best-practices for setting up Aastras (and other phones) to behave nicely
>across firewalls that have SIP ALG *enabled*. Sorry if this is a lame or too
>broad a question. Any tips & tricks you've used are helpful.
>Thanks much,
>Darren Schreiber
>Co-Founder - VoIP, Inc. - (415) 886-7900 www.2600hz.org - Free VoIP Software
>www.voipkb.com - FreeSWITCH Trainings
>VoiceOps mailing list
>VoiceOps at voiceops.org

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