3.2 Packet Format
Figure 3 outlines ExOR's packet header format. The
ExOR header follows the Ethernet header, and is followed
by the packet's data. All ExOR packets are broadcasts. The
Ver ¯eld indicates the current ExOR version, in case of future
protocol changes. The HdrLen and PayloadLen ¯elds
indicate the size of the ExOR header and payload respectively.
The BatchID ¯eld indicates which batch the packet
belongs to. The PktNum is the current packet's o®set in the
batch. This o®set corresponds to the batch map entry for
the packet. The BatchSz indicates the total number of packets
in the batch. FragSz indicates the size of the currently
sending node's fragment (in packets), and FragNum is the
current packet's o®set within the fragment. The FwdList-
Size ¯eld speci¯es the number of forwarders in the list, and
the ForwarderNum is the current sender's o®set within the
list. The Forwarder List is a copy of the sender's local forwarder
list. The source and destination are speci¯ed in the
forwarder list.