[SIPForum-discussion] Max forwards geting added by proxies

[Vijay Kumar]

Vijay

There may be some ambiguty in RFC OK .
My second question is as below iam pasting from original mail in this mail
chain


2. As per 3261 if Max forward Is not added by UAC then SIP outbond proxy
Must add Maxforward header feild.
    Can Max-forwarded be added by intermediate proxies as wel l???

(If yes i feel the  purpose of Max forwards header feild  does not serve
the purpose.)

Regards
Vijay

On Thu, Jan 24, 2013 at 7:39 PM, Vijay Badola <Vijay.Badola at onmobile.com>wrote:

>  There are many places in RFCs that show the contradictory meaning. And
> this also looks as a part of that contradiction.
>
>
>
> Regards,
>
> Vijay Badola
>
>
>
> *From:* discussion-bounces at sipforum.org [mailto:
> discussion-bounces at sipforum.org] *On Behalf Of *Vijay Kumar
> *Sent:* Wednesday, January 23, 2013 7:37 AM
> *To:* Gottfried, Hal F
> *Cc:* discussion at sipforum.org
> *Subject:* Re: [SIPForum-discussion] Max forwards geting added by proxies
>
>
>
> Hal F. Gottfried
>
> Agreed, but my question is that why Proxy should add it.
>
> If an outbound proxy gets a request from a UAC then it may add it  no
> problem.
>
> Can intermediate proxy do this?
>
> Regards
>
> Vijay
>
>
>
> On Wed, Jan 23, 2013 at 4:59 AM, Gottfried, Hal F <
> hal.gottfried at verizon.com> wrote:
>
> Vijay –
>
> I believe the wordings of the RFC are slightly ambiguous when it comes to
> the use of the Max-Forwards field.  There was a time when this field was
> optional although now it has become mandatory. Max-Forwards limits the
> number of hops a request can make on the way to its destination. It
> consists of an integer, normally 70 that is decremented by one at each hop.
> If the Max-Forwards value reaches 0 before the request reaches its
> destination, it is rejected with a 483 (Too Many Hops) error response.
>
>
>
> The real use behind the Max-Forwards mechanism is in that it allows the
> preventing of a message from entering into an endless loop between a set of
> proxies.
>
>
>
> I hope this helps.
>
>
>
> *Hal F. Gottfried*
>
> Sr Consultant, Contact Center Consulting & Services
>
>
>
> *From:* discussion-bounces at sipforum.org [mailto:
> discussion-bounces at sipforum.org] *On Behalf Of *Vijay Kumar
> *Sent:* Tuesday, January 22, 2013 3:25 AM
> *To:* discussion at sipforum.org
> *Subject:* [SIPForum-discussion] Max forwards geting added by proxies
>
>
>
> Agreed as per RFC 3261 Sec 8.1.1.6   " Max forward is Mandatory header
> feild in SIP Requests
>
> UAC MUST insert it."
>
>
>
> But as per 16.6
>
>
>
> "If the copy does not contain a Max-Forwards header field, the proxy MUST
> add
>
> one with a field value, which SHOULD be 70."
>
>
>
> My questions
>
> 1.If MAx forwards is a Mandatory parameter then why should proxy add it.(
> If UAs are not able to add it).
>
>
>
> 2. As per 3261 if Max forward Is not added by UAC then SIP outbond proxy
> Must add Maxforward header feild.
>
>     Can Max-forwarded be added by intermediate proxies as wel l???
>
>
>
> (If yes i feel the  purpouse of Max forwards header feild  does not serve
> the purpose.)
>
>
>
> Enlighten me please
>
> Thanks in Advance
>
> Vijay
>
>
>
>
>
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