RE: iFCP vs FCIP

[Charles Monia <cmonia@NishanSystems.com>]

Hi:

See my remarks below.

> -----Original Message-----
> From: Murali Rajagopal [mailto:muralir@lightsand.com]
> Sent: Tuesday, November 28, 2000 9:35 AM
> To: Ips (E-mail)
> Cc: David Robinson (E-mail); Charles Monia
> Subject: RE: iFCP vs FCIP
> 
> 
> With my TC hat off:
> 
> Charles observation that FCIP's goal to maintain transparency 
> within the
> switching FC Fabric is correct as far data transport is 
> concerned. However,
> there is a clearly defined architecture defined in FC-SW-2 
> standards that
> allow a device such as FCIP to connect to a border switch.
> In  other words,
> from a routing standpoint the FC fabric is certainly aware of 
> a hierarchial
> network and is supported jointly by the FSPF routing protocol and the
> FSPF-backbone routing protocols. This OSPF-based hierarchial 
> model provides
> a lot of flexibility to the nature of the FC backbone networks. TCP/IP
> happens to be one of the many possabilities. (Other 
> possabilities include FC
> directly over ATM and SONET as defined in the ANSI T11 FC-BB 
> standards)
> 

Ignoring the fact that FC-SW2 is newly minted, the point is that the role of
FCIP is limited to interconnecting Fibre Channel SANS. One still needs to
support an FC fabric infrastructure.

A second, equally important consideration, is that iFCP is better positioned
to leverage the enormous investment in IP and ethernet technology.

Others have commented on the fact that the use of IP automatically provides
access to the physical transports you mention.

> The second plus of this model is that it allows any type of 
> traffic and
> allows for a very simple almost stateless (from FC 
> point-of-view) behavior.

The problem with this level of transparency is that it exposes the internals
of each autonomous region connected across the tunnel. Consequently, FCIP
does nothing to mitigate the long-standing problem of interoperability
between FC switches that has plagued Fibre Channel.  Such incompatibilities
can be concealed by an iFCP gateway implementation that provides the same
level of connectivity between end devices while supporting any desired level
of ULP transparency.

> This directly translates to scalability. The comment made by 
> someone in this
> thread about FCIP being limited is inaccurate- it is in fact 
> the opposite.
> 
> Finally, Joshua's comment on the small number of switches in 
> a FC SAN is an
> observation from the past and this is rapidly changing as 
> evidenced by the
> growing size of SANs in Data Centers.
> 

> -Murali Rajagopal
> LightSand Communications
> 

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