Hi Josh,

One last followup: I was curious to see exactly what happens when 
dhclient renews my IP address, so I captured it with wireshark and found 
that in the DHCP request, dhclient specifies the IP address it is 
requesting to be renewed (the same IP that was originally leased). The 
DHCP server finds no problem with renewing that leased IP as the MAC 
address matches the one that currently owns that lease. At the same time 
I renewed my lease I was downloading a Debian ISO. The download was 
maintained and did not break. The reason for this is the device 
transmitting the ISO packets to my computer (my Cisco router) is not 
updating it's ARP table or dropping my computer's MAC from it's table 
just because I renewed my lease on the DHCP server. Heck, it's not even 
sending out a new ARP request for my leased IP as it is oblivious to the 
fact that I renewed my lease on the DHCP server.

Anyway, this should be a definitive answer that renewing a DHCP lease 
will not prevent SIP from working like normal as proved by my testing. 
You can also test this for yourself or perform this test for your 
integrator to verify. The easiest scenario would be to install a 
softphone on your computer and call it when performing this test.

Good luck,
Brandon

On 03/31/2011 10:25 PM, Brandon W. Yuille wrote:
> Hi Josh,
>
> What leads you to believe renewing a DHCP lease will drop your call?
>
> Think about this: have you ever had an HTTP download break because your
> computer needed to renew it's DHCP lease? I've never experienced such a
> thing.
>
> I'm not an expert by any means with DHCP, but if your computer sends a
> renew, why would the DHCP server drop or change that computers IP
> address? If you want expert advice with DHCP, I'd think you'd be better
> off asking this in another mailing list.
>
> My best answer for you would be: DHCP would have been replaced by now if
> renewing a leased address caused the behavior you're describing. Now if
> there is an IP conflict on the network (some other computer has the
> leased IP statically assigned), then yes you most defiantly would have
> issues.
>
> I hope I was able to help,
> Brandon
>
>
>
> On 03/31/2011 05:42 PM, Josh Roberts wrote:
>    
>> Mayank and friends,
>>
>> I'm trying to authenticate a statement by a voip/sip system integrator that
>> dhcp has stability and reliability issues because when the phone rings
>> (every time, according to this company) it has to check its lease for
>> renewal and potentially renew the lease before the call can connect.
>>
>> Thanks for your time,
>> Josh
>>
>> On Thu, Mar 31, 2011 at 09:30, Mayank Jain<[email protected]>   wrote:
>>
>>
>>      
>>> On 3/31/2011 9:04 AM, Josh Roberts wrote:
>>>
>>>
>>>        
>>>> Resending, and hoping for a response. To avoid spamming, I won't resend
>>>> again. Please advise if I should be posting to a different list.
>>>>
>>>> On Sat, Mar 26, 2011 at 15:00, Josh Roberts<[email protected]>    wrote:
>>>>
>>>>    Anybody have:
>>>>
>>>>          
>>>>>      1. any rfc reference for best practice on voip deployment regarding
>>>>>
>>>>>      whether to use a static/dynamic ip?
>>>>>      2. any rfc material on how a voip/sip client should/must handle a 
>>>>> dhcp
>>>>>
>>>>>      lease check/renewal when receiving a call from its server?
>>>>>
>>>>>
>>>>>            
>>>> Can you elaborate more on your requirements. I think people don't
>>>>
>>>>          
>>> understand what exactly you want to do. If you can give a detailed
>>> description then it will be helpful for people to answer.
>>>
>>> Regards,
>>> Mayank Jain
>>>
>>>
>>>        
>>>> Thanks for your time,
>>>>
>>>>          
>>>>> Josh
>>>>>
>>>>>    _______________________________________________
>>>>>
>>>>>            
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>>>>
>>>>
>>>>
>>>>
>>>>          
>>>
>>>        
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