Re: Question on LMP.

[Zafar Ali <zali@cisco.com>]

At 02:56 PM 4/16/2002 +0200, Michiel van Everdingen
wrote:
> Zafar,
>
> Could you please clarify what is 'CC' ?

Sorry Michiel, I should have been more clear on this... 

CC = Control Channel in my message.

Thanks

Regards... Zafar 
> I've tried to read your email assuming
> 'CC'=Cross Connect and
> assuming 'CC'=Connection Controller, but failed.
>
> I assume
>   'SDCC' = section DCC / RS-DCC (D1-D3)
>   'LDCC' = line DCC / MS-DCC (D4-D12)
> correct ?
>
> What is an SDCC/LDCC based CC ?
> What is an interface bound IPCC ?
>
>
> Please accept my apologies if these terms are well-known to this
> group.
>
>
> Thanks,
>
> Michiel
>
>
> Zafar Ali wrote:
> > 
> > At 03:22 PM 4/15/2002 +0530, Manoj Sontakke wrote:
> > 
> > > Hi Jonathan,
> > >
> > > Thanks for the quick response. Please see my comments
> inline.
> > >
> > > Manoj
> > >
> > > Jonathan Lang wrote:
> > > >
> > > > Manoj,
> > > >   Please see inline.
> > > >
> > > > Thanks,
> > > > Jonathan
> > > >
> > > > > -----Original Message-----
> > > > > From: Manoj Sontakke
> [mailto:manojs@sasken.com]
> > > > > Sent: Thursday, April 11, 2002 7:02 AM
> > > > > To: ccamp@ops.ietf.org
> > > > > Subject: Question on LMP.
> > > > >
> > > > >
> > > > > Hi,
> > > > >
> > > > > I have two questions on LMP.
> > > > >
> > > > >
> --------------------------------------------------------------
> > > > > -----------------------------
> > > > > Q1.  Control Channel Question
> > > > >
> > > > > Assuming a configuration as shown.
> > > > >
> > > > >
> > > >
> >                
> -----------------              
> -----------------
> > > >
> >                
> |              
> |              
> |              
> |
> > > >
> >                
> |           
> if1|---------------|if1           
> |
> > > >
> >                
> |           
> if2|---------------|if2           
> |
> > > >
> >                
> |     OXC 1    
> |              
> |     OXC 2     |
> > > >
> >                
> |            
> d1|---------------|d1            
> |
> > > >
> >                
> |            
> d2|---------------|d2            
> |
> > > >
> >                
> -----------------
> > > > > -----------------
> > > > >
> > > > >
> > > > > I have two OXCs connected by four links. Consider d1,
> d2 are configured
> > > > > to carry data and if1 and if2 are configured to carry
> control data ( LMP
> > > > > messages and RSVP and OSPF messages).
> > > > >
> > > > > The LMP document defines control channels with an
> unique identifier (
> > > > > control channel identifier ) between the negibouring
> nodes.
> > > > > So also, the LMP messages are IP encapsulated.
> > > > >
> > > > > Now, I have a couple of questions
> > > > >
> > > > > 1. Is there any association between the LMP control
> channels to the
> > > > > physical interfaces( if1, if2). Because all the IP
> packets are routed on
> > > > > the physical interfaces according to the routing
> table. The control
> > > > > channel messages like  ( config and configAck
> etc.. ) can go on the any
> > > > > physical interface which is decided by the routing
> table.
> > > > >
> > > > > In such case, are the control channels a pure logical
> concept or do they
> > > > > have any physical interface significance &
> correlation [ mapping between
> > > > > control channles ( ccid ) and interfaces ( if1 and
> if2 )] ?
> > >
> > > > Control channels are associated with interfaces.
> > >
> > > Manoj-> The draft does not say so explicitly. Besides, all
> the LMP
> > > messages are IP encoded. So the routing table decides the
> outgoing
> > > interface for sending the LMP messages (any packet for that
> matter)
> > > depending upon the destination IP address.
> > >
> > > So is it possible to make such an association between the LMP
> control
> > > channel and a physical interface (though it is 
> desirable)?
> > 
> > Hi Manoj, et all:
> > 
> > The association between the CC and data bearer link is neither
> prevented nor enforced by the specification, as you also mentioned. IMO,
> the association between the CC and data bearer link is a vendor specific
> question. Vendors can manage the available set of CCs in the way they
> would like to.
> > I.e., a vendor may choose a specific CC to send all messages that
> are pertaining to a data bearer link, etc. The key is that the receiver
> node for the LMP messages should be able to receive LMP messages from any
> CC that it’s running with a given neighbor. This is of course with the
> exception of
> > LMP Hellos messages.
> > 
> > > Are we
> > > deviating from the standard IP implementation ?
> > 
> > In selecting the CC by making an association between the CC and the
> data link, one will NOT be diverting from IP. Specifically, one may
> consider CC to be of two different types: interface bound or routed.
> E.g., SDCC/ LDCC based CCs can be regarded as interface bound IPCCs. LMP
> application can
> > select a specific egress interface while using interface bound CCs,
> etc.
> > 
> > Thanks
> > 
> > Regards… Zafar
> > 
> > <snip>