Verizon Wireless LTE/4G and SIP Header Manipulation

William McCall william.mccall at gmail.com
Tue Sep 22 19:57:58 UTC 2015


I've seen this behavior before (a few years back). Moved off of VzW for
this reason (i'm lazy to implement workarounds).

IIRC when i investigated, the ALG was trying to not do something nefarious
but just poorly implemented.

On Tue, Sep 22, 2015 at 12:51 PM, Christopher Morrow <
morrowc.lists at gmail.com> wrote:

> On Tue, Sep 22, 2015 at 12:22 PM, Christopher Morrow
> <morrowc.lists at gmail.com> wrote:
> > On Tue, Sep 22, 2015 at 12:03 PM, Mark Stevens <manager at monmouth.com>
> wrote:
> >> Hi All,
> >>
> >> Has anyone seen that something (most likely an alg) on Verizon's LTE/4G
> >> network is rewriting SIP headers,in particular From Tag identifiers? We
> >> cannot make a SIP call from our cellphones (using cellular data) beyond
> 30
> >> seconds because the TAGs are rewritten and the destination Asterisk
> server
> >> drops the call because of this.
> >>
> >
> > I'm shocked that the cellular carrier is making over-the-top phone
> > calls non-functional. I'm sure they'll agree to meet you at their CO
> > so you can do the proper work request sometime between 6am and 7pm in
> > 2 weeks time.
> >
>
> joking aside, are you sure the packets get mangledin VZW and not
> elsewhere along the path? how would you be able to prove it?
>
> > go incombancy!
> >
> >> Thanks
> >>
> >> Mark
>



-- 
William McCall



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