[asterisk-dev] Via/maddr: (was Re: [Code Review] Properly route responses according to the Via headers in the request)

Klaus Darilion klaus.mailinglists at pernau.at
Tue Jan 4 05:26:21 CST 2011

Am 04.01.2011 10:07, schrieb Olle E. Johansson:
> 4 jan 2011 kl. 09.34 skrev Klaus Darilion:
>> Am 03.01.2011 21:05, schrieb Simon Perreault:
>>> On 01/03/11 12:30, Klaus Darilion wrote:
>>>> Actually they can rather easy tell you where to send response - they
>>>> just have to send from this certain IP address (in case of UDP).
>>>> Thus I think maddr is a "bug".
>>> maddr is intended to contain a multicast address. In general you can't
>>> just use this kind of address as source without breaking a ton of other
>>> things (e.g. ICMP replies come to mind).
>> Ok, this makes sense. But why should a response be sent to a multicast address at all?
> If the request was sent to multicast, it's a natural result to send the response there too,
> to make sure that all recipients of the request got the response.
> Now, I haven't seen many implementations of SIP over Multicast. It is used as a
> test on every SIPit and makes all phones ring...

So we could make a "SIP day" and ring all SIP phones in the world :-)

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