The MPLS WG Archive

["Rutemiller, John" <John.Rutemiller@marconi.com>]

Curtis,

> Network stability is more important goal than measurement accuracy.
> Scalability is an important goal (see RFC1958 Architectural Principles
> of the Internet).  Here's a sample:
> 
>    3.3 All designs must scale readily to very many nodes per 
> site and to
>    many millions of sites.
> 
>    3.4 Performance and cost must be considered as well as 
> functionality.
> 
>    3.5 Keep it simple. When in doubt during design, choose 
> the simplest
>    solution.
> 
>    3.6 Modularity is good. If you can keep things separate, do so.
> 
>    3.7 In many cases it is better to adopt an almost complete solution
>    now, rather than to wait until a perfect solution can be found.


So based on items 3.5 and 3.6, you advocate an MPLS-OAM solution. :)

3.5 Keep it simple
- MPLS-OAM uses a single one-way message to check the health of the LSP.
- ICMP/LSP-PING requries two two-way messages.

One vote for MPLS-OAM.

3.6 Modularity is good.
- MPLS-OAM is confined to the data plane under test.
- ICMP/LSP-PING involves the data plane under test(LSP), a data plane
  not under test (IP) and a control plane.

One more vote for MPLS-OAM.

MPLS-OAM can meet 3.3 and 3.4. ICMP was implemented in hardware. You
can do the same with MPLS-OAM.

I think one of the arguments against ICMP/LSP-PING is that it does not
satisfy 3.7. It is not almost complete. It is lacking what many consider
significant functional capabilities.

John