Hello Supriya,
SAP Note 421359 validity date is 06.09.2007. It pertains to binding ports on unix and i am running a standalone SAP Web dispatcher version 7.20 patch 421 with a NW 7.30 backend.
I already have a working Web Dispatcher using the identical profile parameters pointing to the identical Central Instance. The only thing I have not dione is do a Global Invalidation of the ABAP server cache.
Regards,
Dan Mead