RE: Two Drafts for Resilience of Control Plane

["Zafar Ali \(zali\)" <zali@cisco.com>]

> -----Original Message-----
> From: Igor Bryskin [mailto:i_bryskin@yahoo.com] 
> Sent: Friday, October 28, 2005 11:50 AM
> To: Zafar Ali (zali); Kim Young Hwa; ccamp@ops.ietf.org
> Subject: RE: Two Drafts for Resilience of Control Plane
> 
> Zafar,
> 
> The problem arises when the control plane is decoupled from 
> the data plane. 

But control network is still (and needs to be) an IP network. 

>The question is do we need such decoupling in 
> IP networks? Consider, for example, the situation when 
> several parallel PSC data links bundled together and 
> controlled by a single control channel.

If this "single control channel" is "IP routing" the control packets, as
long as there is resilience in the control network (i.e., alternate IP
routes), we should be see "single control channel" as a deficiency. It's
as best of resiliency that it gets. 

> Does it mean in this case that when the control channel fails 
> all associated data links also fail? 
> Do we need to reroute in 
> this case LSPs that use the data links? 

We have (RSVP/ LMP) GR procedures for recovery of control network
failures. 

>Can we rely in this 
> case on control plane indications to decide whether an 
> associated data link is healthy or not (in other words, can 
> we rely on RSVP Hellos or should we use, for example, BTD)? 
> Should we be capable to recover control channels without 
> disturbing data plane? 

All these things are already addressed, please also see Dimitri's email
on this. 

> I think control plane resilience is 
> important for all layers. 

What is your definition of layers here? What I am saying is that having
control network resilience build outside IP layer is "bad complexity". 

> You are right, Internet does work, 
> however, we do need for some reason TE and (fast) recovery in 
> IP as much as in other layers,don't we?
> 
> Cheers,
> Igor
> 
> --- "Zafar Ali (zali)" <zali@cisco.com> wrote:
> 
> > Hi All,
> >  
> > I am unable to understand the problem we are trying to solve or 
> > fabricate. My control network is IP based and IP has proven 
> resiliency 
> > (Internet *does* work), why would I like to take control plan 
> > resiliency problem at a layer *above-IP* and complicate my 
> life. Did I 
> > miss something?
> >  
> > Thanks
> >  
> > Regards... Zafar
> > 
> > 
> > ________________________________
> > 
> > 	From: owner-ccamp@ops.ietf.org
> > [mailto:owner-ccamp@ops.ietf.org]
> > On Behalf Of Kim Young Hwa
> > 	Sent: Friday, October 28, 2005 6:04 AM
> > 	To: ccamp@ops.ietf.org
> > 	Subject: Two Drafts for Resilience of Control Plane
> > 	
> > 	
> > 	Dear all,
> > 	 
> > 	I posted two drafts for the resilience of control plane.
> > 	One is for requirements of the resilience of control 
> plane, the other 
> > is for a protocol specification as a solution of that .
> > 	These are now available at:
> > 	
> >
> http://www.ietf.org/internet-drafts/draft-kim-ccamp-cpr-reqts-01.txt
> > 	
> >
> http://www.ietf.org/internet-drafts/draft-kim-ccamp-accp-proto
> col-00.txt
> > 	 
> > 	I want your comments.
> > 	 
> > 	Regards
> > 	 
> > 	Young.
> > 	 
> > 	====================================
> > 	Young-Hwa Kim
> > 	Principal Member / Ph.D
> > 	BcN Research Division, ETRI
> > 	Tel:     +82-42-860-5819
> > 	Fax:    +82-42-860-5440
> > 	e-mail: yhwkim@etri.re.kr
> > 	====================================
> > 	
> >
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> 
> 
> 
> 	
> 		
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