Appeal No. 2004-0852
Application No. 09/354,651 Page 7
routed from the source to the destination over a path which is
available in order to route the packet from the source to the
destination during the data phase.
Appellants respond (reply brief, page 2) that in Rekhter,
upon receipt of a packet, the tags are utilized to determine
which router to forward the packet to. Appellants add (id.) that
the CEs, which connect the customer private network sites via the
operator network have no knowledge and do not need to have any
knowledge of the tags that are employed in the routers of the
operator network.
From our review of the entire record, we find that in
Rekhter, the transit routers base their routing decisions on
packet fields that the transit (P) routers interpret without
reliance on virtual private network (VPN) specific routing
information (col. 3, lines 59-65). In describing one way to tag
a packet, Rekhter discloses that different link-level protocols
may be employed. An example of a protocol is a point-to-point
protocol. Links in the IEEE 802 protocol family are similar to
the Ethernet protocol. If the links connecting CE2 to PE2 are
Ethernet links, the link-layer frame takes the form of figure 2's
top row, consisting of a link-level payload encapsulated by an
Ethernet header and trailer. The Ethernet trailer consists of
Page: Previous 1 2 3 4 5 6 7 8 9 10 11 Next
Last modified: November 3, 2007