The MPLS WG Archive

[Jing Shen <jshen@cad.zju.edu.cn>]

Curtis,


> 
> In message <3DF48F65.840949E1@cad.zju.edu.cn>, Jing Shen writes:
> >
> > OMP gives a good start on traffic engineering but its traffic division
> > policy is too simple for self-similar internet traffic.
> 
> I don't see any basis for this assertion.
> 
> The IP src/dst hash is used almost universally in ECMP for OSPF, ISIS,
> LDP (after payload snooping consistently indicates that payload is
> IP), and MPLS/TE implementations (when L3PID indicates IP traffic), as
> well as in proprietary link bundling (for example: Avici Composite
> Links (tm) and others).  It works very well with Internet traffic.
> 

First of all, I take OMP is very good start in trying to make use of
idled network resource. And it shows good performance in simulation and
the academic testbed you mentioned. 

We take multipath routing is the way to make full use of network
resource
and traffic dispersion should be done according to the state of network
but
not the the src/dst hash function. The reason is, network load is not
symetricly
distributed and LRD is the built-in properties. So, even there exists 
multiple equal cost path between any src-dst pair hash based traffic
division
will not lead to a balanced network usage as well as guaranteeing e2e
qos.




> > I have another question, is OMP implemented in some commerical products?
> > if not, why?
> 
> There have been a few research implementations that have come to my
> attention, mostly grad student projects.
> 
> Implementing in a commercial router is a much larger undertaking due
> to added complexity (forwarding cards are separate from router
> processors, more is done in hardware or microcode, 100s or 1000s of
> interfaces pose greater scaling challenges, etc) and the software
> quality requirements.  Without a customer expressing strong interest
> this hasn't happenned.
> 

Thanks for the verification. I think this is for the same reason that
the network is usually overprovisioned, so people take it enough.

if there is something wrong correct me please.



-- 
Jing Shen

State Key Lab of CAD&CG
ZheJiang University(YuQuan)
HangZhou, Z.J. 310027
P.R.China

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