RE: Differentiated Routing, not only plain rambo-SPF

Senthil,

-> I am also sceptical of the following issues:
-> 
-> - scalability: Since you are maintaining multiple Routing
-> tables, doing at line rate is pretty difficult and hence
-> doesnt scale well.

  I agree with you here. Yes! there are performance and
  scalability problems if we go for DiffRouting in a 
  hop-by-hop fashion. Then you have to maintain
  different route tables, line rate forwarding issues etc etc.

  That is why we went for source routing (using MPLS-TE).
  That effectively solved the problem of maintaining 
  multiple routing tables. Connection-less to connection-oriented
  move (with small fixed length label lookup) solved the 
  problem of line rate forwarding (directly or indirectly).
  
  Now we are moving towards MPLS-TE with DiffServ.

  Source routing also has scalability issues. This is yet to
  be solved!

-> - complexity: This work increases the complexity at per 
-> router level. Some people complain of increase in complexity 
-> for just adding three more lines in the original forwaring algo
-> (to include RED features.) I dont know  how much complex
-> the router becomes because of diffrout.

  Weight complexity with performance.
 
-> - end to end: Diffserv is defined only for edge to edge. How will 
-> diffrout behave when considering end to end is still open.

  Yes! This is what I am concerned about.

--
Venkata.