RE: iFCP - FCIP merge proposal

[Joshua Tseng <jtseng@NishanSystems.com>]

Venkat,

> 
> Josh,
> 
> I can see iFCP draft document changed to support for 
> NL_Ports, but I fail to

Once again, the iFCP document as it exists today supports
loop ports.  In the document, N_PORT is a generic term used
to refer to N_PORTs and NL_PORTs.

> see a trivial mapping to include E_Port or B_Port 
> functionality. Certainly
> an ISL with one end connected to a pure FC switche's E_Port 
> and the other
> end connected to an N_Port on a device with iFCP Portal would 
> not work. Are
> you suggesting that the device with iFCP portal would also 
> provide an E_Port
> connectivity? If so, who selects Principal Switch? Are you 

E_PORT is specified already in FC-SW-2.  Everything you need
to implement E_PORT is already in that spec.  An iFCP gateway
could implement it as well, in order to interoperate with
Fibre Channel fabrics.  How you actually do it is internal
to the gateway box and is not within the scope of either
iFCP or FCIP.

> also prepared to
> encapsulate Class F Frames in IP and send it to another 
> switch during the
> Principal Switch selection phase of initialization?

No, this is not a feature of iFCP.

> 
> If we simply let these as "implementation details", I am not 
> sure how one
> can ensure interoperable collection of switches that support 
> a combined FC
> and IP network. 

If the iFCP gateway implements FC-SW-2, then it should be
interoperable with the FC network.  If the gateway implements
iFCP, then it will be interoperable with iFCP gateways.
How you actually map FC-SW-2 to iFCP is internal to the gateway
box.  It is implementation detail that is outside the scope of
FC-SW-2 and iFCP.

> Is it not a requirement to support these 
> environments? The

All I am saying is that these environments can be supported with iFCP
implementations.  For a user who wants to continue using their existing
FC switches, then they will need an iFCP gateway implementation that
also implements both FC-SW-2 and iFCP.  If they are fed up with their
Fibre Channel switches and they simply want to throw them away, then
all they need is a gateway that implements iFCP.

> FCIP proposal, by relying on FC-SW-2 concepts for the SAN islands, and
> providing FC-BB for IP connectivity between SAN islands along with FC
> encapsulation over IP, provides this capability fairly 
> seamlessly without a
> whole new architecture.

I agree.  You get both the same benefits and weaknesses of the old FC
architecture.  Perhaps that is acceptable to many, but others may need
to scale up to IP fabrics.  iFCP is for users who need the interoperability,
scalability, and commodity pricing that IP/Gig E already provides.

Regards,

Josh

> 
> Regards,
> 
> Venkat Rangan
> Rhapsody Networks Inc.
> http://www.rhapsodynetworks.com
> 
> -----Original Message-----
> From: Joshua Tseng [mailto:jtseng@NishanSystems.com]
> Sent: Thursday, December 14, 2000 8:55 AM
> To: Venkat Rangan; Julian_Satran@il.ibm.com; ips@ece.cmu.edu
> Subject: RE: iFCP - FCIP merge proposal
> 
> 
> Venkat,
> 
> <stuff deleted...>
> >
> > But as far as I can tell, iFCP requires you to remove devices
> > that support
> > E_Port, B_Port and FC-AL functionality and replace them 
> with iFCP plus
> > OSPF/BGP/RIP implementaions, which is quite a drastic step
> > for a deployed
> > SAN to take on. Merging the two would appear to provide both
> > capabilities.
> >
> iFCP does not require you to remove anything.  There are 
> implementation
> techniques to connect E_PORTS, Loop ports, and whatever ports you have
> in FC to the iFCP transport.  Merging the two will provide you nothing
> but a very complicated, confusing document describing two dissimilar
> techniques.
> 
> Regards,
> 
> Josh
> 
> > Regards,
> >
> > Venkat Rangan
> > Rhapsody Networks Inc.
> > http://www.rhapsodynetworks.com
> >
> >
> > -----Original Message-----
> > From: owner-ips@ece.cmu.edu 
> [mailto:owner-ips@ece.cmu.edu]On Behalf Of
> > Julian Satran
> > Sent: Wednesday, December 13, 2000 4:36 PM
> > To: ips@ece.cmu.edu
> > Subject: iFCP - FCIP merge proposal
> >
> >
> > Dear colleagues,
> >
> > At yesterdays IPS WG meeting and had no chance to clarify 
> my proposal
> > regarding a merger of FCIP and iFCP into a single effort.
> >
> > iFCP attempt to provide an IP interconnect for FCP devices.
> > It has also the
> > capabilty to interconnect FC islands.
> >
> > FCIP has the narrower scope of connecting only FC islands -
> > admittedly even
> > FC devices other then FCP.
> >
> > Given that FCP devices where the main concern of this WG 
> and that iFCP
> > serves a wider purpose than FCIP and will enable not only
> > tunneling but also
> > migration of FCP devices to IP infrastructure my intention
> > was to suggest
> > that iFCP should attempt to incorporate those FCIP functions
> > it does not
> > care about today and those two groups should work towards one
> > common draft
> > that should cover not only tunneling but also device migration to IP
> > networks.
> >
> > Julo
> > ______________________________________________________________
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