Verizon Wireless LTE/4G and SIP Header Manipulation

Tue Sep 22 20:16:28 UTC 2015

The TAG unique identifier is being changed and this only happens through 
VZ LTE networks, not wired networks or even other cellular data networks 
(Sprint, ATT, T-Mobile)
Their phones are IPV6 so the packets are getting converted to IPV4 so it 
is either happening there or there is a global ALG in Verizon land that 
is doing it .
For positive proof I would need Verizon to fess up (LOL) but that will 
not happen or sniff traffic from the cellphone itself.

On 9/22/2015 3:51 PM, Christopher Morrow 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