[Css-dts] Significance of the functional group component of the Service instance Identifier

[John Pietras]

Members of the DTSWG,
I have recently "rediscovered" that the Service Instance Identifier for
SLE transfer services has a Forward/Return Service Functional Group
component which appears to name a specific instance of a forward space
link functional group (fsl-fg) or return space link-functional group
(rsl-fg). The example from the FCLTU Blue (2) Book is
'sagr=xyz.spack=abcdef.rsl-fg=gfjdy.raf=onlc2'. The SLE transfer service
specifications further states that "the value of [the Forward/Return
Service Functional Group] is to be agreed between the user and the
provider."

Is this FG just a logical identifier that is included in the service
instance ID, or is the intention that there will be some physical or
logical entities associated with these FG names that must somehow be
configured to support the production or provision of the service
instance? Currently, SLE-SM does not recognize functional groups. I
would like to understand the intention behind this FG name so that we
can assess what (if any) changes are required in SLE-SM.

I apologize for not thinking of the ramifications of this FG component
when this shortened identifier convention was first proposed (and then
subsequently adopted). 

Thank you for your consideration of this topic. I look forward to seeing
many of you in Athens (a mere month from today!)

Best regards,
John