Subject: OSPF_TE and DS

From: Arkadiusz Binder <[email-masked]>
Date: Sun, 14 Dec 2003 03:28:02 +0100

Hello good people !

My ask is,
will you consider in enabling onto some LSA / TLV to distribute DS polices
between OSPF domain ?

I see that importing/redistributing routes at the ASBR could take some
unified action of classyfing packets by some rulez, to set them TOS or DS
(AF's) .
The redistribution of that could be in extended command syntax - such as
area range.
The problem point is to define the source/dest of our DS group, to do best
understand all of the rulez, which must be taken at the egres ASBR router.
1. When route is inside OSPF network, then nothing happen (just we behave on
ourselves DS.in=DS.out) - which might be configurable too (or already it is
enabled by auto, when setting maximum reservable bandwith for each TOS or
precendence)
2. When route (packet) exits from our OSPF network, and is going oudisde
domain by egres ASBR, then the TOS field will be cleaned automatically
(egres router know how to behave from ingres ASBR which has orginated rulez
for such routes/DS)

I think, that this Policy Distribution should be enabled into routing
protocol, just because in large networks we could meet some QOS
misconfigurations based on human mistake. I dont know now any other
automated system of distributing such rulez between routers. Is it a good
concept ?

To not pollute list, i can't find everywhere answer for that:
In Constraint Based Routing, based on OSPF_TE, could we dynamically
calculate costs for different TOS based on the actually bandwidth usage of
local interfaces/ Interfaces of other OSPF domain routers ?
the concept is:

A---C---Internet
|   |
|   |
B---+

Current state A->C has 100% bandwidth used (80% NORMAL-TOS, 20%
NO-TRANSMIT-TOS)
Current needs A->C wants 150% bandwidth (120% NORMAL-TOS, 50%
NO-TRANSMIT-TOS) -> we do some policy of queue over 100%...
Current needs (after DS policing) A->C = 100% NORMAL-TOS +20%
NO-TRANSMIT-TOS + 50% NO-TRANSMIT-TOS.
Consider link A->B->C is empty at the moment,and i wand all NO-TRANSMIT-TOS
for the same route 0/0 to go via A->B->C .

If it is possible, please explain me, which of TLV are dynamically changing
when traffic queues exceeds / drops .

We want to create some new labolatories for students, to
test,,,test,,,test,,,

Arkadiusz Binder

sorry for my english.

---

From: Acee Lindem <[email-masked]>
Date: Sun, 14 Dec 2003 11:22:29 -0500

Hi Akadiusz,

For your experimentation, why don't you start by using the AS external
route tag to carrid DS code point policy?

Thanks,
Acee

-- 
Acee

---

From: Arkadiusz Binder <[email-masked]>
Date: Mon, 15 Dec 2003 04:29:57 +0100

> route tag to carrid DS code point policy?

Well, it's good idea :)
but what with MPLS - OSPF + MP-BGP - the TAG is used for other purposes,,,
if we can map some group of TAG for one VRF it will be polite for all
solutions...

Now i must check if MP-BGP can carry multiple routes for multiple TOS/DS
learned from OSPF or if it is matter for that issue.
(From this moment, I thing, that grouping multiple tags for one VRF, each
with some DS policy will be possible to let this working OK)

Well. i see many other unknown problems (i'm constructing a help site) which
culdn't be explained.

If we enable OSPF_TE+ MPLS capable network, then packets are swiched trough
extra MPLS header, which no logner has TOS - it has CoS (Experimental and
with less (3 bits)) - so PHB with MPLS services seems to be destroyed in
full possibilites - PRECEDENCE ip is destroyed(unaviable) at the transport
level.

I've tried to ask over many list groups for contraint based routing, all
examples behaves on using RSVP protocol, which inform about reservation.
I cant find nowhere if it is possible and how,,, to tell OSPF_TE instance,
that some link is overloaded.
Is TLV with "Unreserved Bandwidth" = "router traffic % counter (aviable)"
correct for telling OSPF_TE domain that some link could be used for extended
traffic by different phisical router path?
If yes, i;m looking for such ready applications (dedicated or some
OpenSource for Linux).
RFC 2211 says something like :"the controlled-load service described here
may be
   invoked by a number of mechanisms, including RSVP, SNMP network
   management software, or proprietary control software. However, any" - so
was right that there is no other (existing in RFC) possiblility (hardware
connections with router and OSPF instance) to tell something about currently
used(other words reserved) bandwidth on some router LINK/class?.
 In MPLS network we have to deal only with TOS (CoS) capabilites (uless MPLS
transit router cant look without upacking packet onto packed L3 TOS field) ,
so DS services here aren't possible here, and seems to be soon dead (or can
be used only in some special cases - (loose / explict routes).

Can somebody comment out my threat ?

A.Binder