When a request reaches the proxy, if mf becomes 0 once proxy decrements 
the mf,then it means it has already hopped n number of times right, then 
why proxy should send to next hop.

i mean, see this example where mf is 5
mf=5    mf =4            mf =3          mf =2         mf =1         mf =0
UA1--> Proxy A--> Proxy B--> Proxy C-->Proxy D--> Proxy E-->UA2

Now at Proxy E mf is 0, means it has already visited 5 nodes, so it 
shdn't be forwarded anymore,so proxy E shd return with 483 response.

Please correct me if i am  wrong.

-Subramanya


Kasturi Narayanan wrote:
> The approach suggested by Robert Sparks solves the problem but creates an 
> un-necessary hop when the sender knows for sure that it going to be dropped 
> by the Receiver (since it is sending with mf=0).
>
> Kasturi
>
> -----Original Message-----
> From: Song, Youngsun [mailto:[EMAIL PROTECTED] 
> Sent: Monday, November 13, 2006 9:22 AM
> To: [email protected]
> Subject: [Sip-implementors] FW: Query on max-forwards counts
>
> Hi,
>
> Please see the attached response from Robert Sparks regarding this
> query. (FYI, I had also sent him a separate email...)
> Per his response, Proxy-B should forward the request to UA-B.
>
> Thanks to all who has taken the time to respond to my query,
> YoungSun
>
>
>   
>> -----Original Message-----
>> From: Robert Sparks [mailto:[EMAIL PROTECTED] 
>> Sent: Monday, November 13, 2006 9:12 AM
>> To: Song, Youngsun
>> Subject: Re: [Sip-implementors] Query on max-forwards counts
>>
>> See page 95, item 3.
>>
>> You reject when you receive, not before you send.
>> You reject when you receive a max-forwards of 0, not when you 
>> receive a max-forwards of 1.
>>
>> RjS
>>
>>     
>>>>> -----Original Message-----
>>>>>           
>>>> From: [EMAIL PROTECTED]
>>>> [mailto:[EMAIL PROTECTED] On 
>>>>         
>> Behalf Of Song, 
>>     
>>>> Youngsun
>>>> Sent: Friday, November 10, 2006 11:19 AM
>>>> To: [email protected]
>>>> Subject: [Sip-implementors] Query on max-forwards counts
>>>>
>>>> Hi,
>>>>
>>>> I have a clarification question on the following statement 
>>>>         
>> in Section
>>     
>>>> 8.1.1.6 of RFC3261 regarding when a proxy should send a 483 and 
>>>> whether the number of hops includes the destination hop.
>>>>
>>>> "The Max-Forwards header field serves to limit the number 
>>>>         
>> of hops a 
>>     
>>>> request can transit on the way to its destination.  It 
>>>>         
>> consists of an 
>>     
>>>> integer that is decremented by one at each hop.  If the 
>>>>         
>> Max-Forwards 
>>     
>>>> value reaches 0 before the request reaches its 
>>>>         
>> destination, it will 
>>     
>>>> be rejected with a 483(Too Many Hops) error response."
>>>>
>>>>
>>>> Consider the following flow: (mf=max-forwards)
>>>>
>>>>
>>>> UA-A --- INVITE (mf=2) ---> Proxy-A ---- INVITE (mf=1) 
>>>>         
>> ---> Proxy-B 
>>     
>>>> ---- INVITE (mf=0) ---> UA-B
>>>>
>>>>
>>>> In the flow above, should Proxy-B forward the INVITE with 
>>>> max-forwards=0 to UA-B or should it reject the request with 483?
>>>>
>>>> Thanks for your help in advance,
>>>> YoungSun
>>>>
>>>> _______________________________________________
>>>> Sip-implementors mailing list
>>>> [email protected]
>>>> https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
>>>>
>>>>         
>>     
>
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>
>   

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