[ih] More terminology (Was: multi-protocol routers, bridges)

[Brian E Carpenter]

On 28-Nov-21 15:46, Carsten Bormann via Internet-history wrote:
> On 28. Nov 2021, at 00:32, Noel Chiappa via Internet-history <internet-history at elists.isoc.org> wrote:
>>
>> We distinguished between two very different activities which 'routers'
>> performed; the handling of user traffic, which we called 'forwarding', 
and the
>> computation of routing data/tables (by routing protocols/algorithms), which
>> was often (but not always, IIRC) called 'routing'. (Slightly confusing, I
>> know! :-)
> 
> Indeed, but both meanings of “routing” prevail.
> I’ll call them routing1 and routing2, where routing1 is defined 
as the combination of routing2 and fowarding.
> 
> We’ll use routing1 when describing the overall outcome, as in “xyz does not route that traffic”, or in “router”.
> 
> We’ll use routing2 together with forwarding when it comes to how to implement routing1; RIB and FIB are clear examples of distinct concepts relating to routing2 and forwarding.  Routing protocols rarely provide forwarding and therefore are routing2.
> (A router that uses strict source routing or an SDN setup does not do routing2 at all…)
> 
> The terms control plane and data plane are another attempt to slice this cake; I must admit I don’t know when those gained popularity.

There's also "fast path" and "slow path" (roughly, hardware vs firmware), 
a popular distinction when discussing tricky issues like handling IPv6 extension headers at line speed. It's also fairly useless for protocol design, because every router vendor has a different approach to this distinction, as far as I can tell.

    Brian

> 

> Grüße, Carsten
>