Re: [port-srv-reg] we need to make progress

[Joe Touch <[e-mail]>]

On 9/7/2010 4:28 PM, Stuart Cheshire wrote:
> On 7 Sep, 2010, at 11:51, Joe Touch wrote:
>
>>>>> This implies that a given service name can have *different* port
>>>>> numbers assigned for different transport protocols.
>>>>
>>>> That is correct, and always has been.
>>>
>>> Can you give an example?
>>
>> DNS and NFS.
>
> DNS is 53 on TCP and 53 on UDP.
>
> NFS is 2049 on TCP and 2049 on UDP.
>
> Can you give an example where a given service name has *different* port
> numbers assigned for TCP and UDP?

Not yet. That's always been possible, and we need to reserve the right 
to do that to conserve the port number space.

That's the whole point of not giving out the UDP if only TCP is needed 
(and the converse) - we can assign them to other protocols later, and if 
we end up needing a corresponding port on another protocol we can assign 
a different number. If we ensured that we'd always give matching 
numbers, there would be no point to giving out only the protocols requested.

Joe