Brief overview of WDS
Windows Deployment Services (WDS) enables Windows OS deployment on client machines over the network. To achieve this WDS uses standard network protocols (like PXE over DHCP, TFTP... etc) and a custom multicast protocol (Multicast Transport Protocol and Multicast
Application Protocol). WDS is currently being used by various orgranizations along with Microsoft OEM and ODM partners.
Protocol Details (involving parser changes) -
Multicast Transport Protocol -
The WDS Multicast Transport Protocol is a multiple clients/single server protocol. The protocol, in conjunction with the WDS Multicast Application Protocol, allows transmission of content to multiple clients using multicast UDP. The protocol provides the best
effort mechanism for delivery of data to all clients. The protocol provides mechanisms to allow clients to join a multicast session at any.
Multicast Application Protocol -
WDS Multicast Application Protocol is a single server, multiple client protocol. The protocol uses WDS Multicast Transport Protocol for transmission of content to multiple clients. The protocol relies on services provided by the WDS Multicast Transport Protocol
to ensure all pieces of content are delivered to all clients in a multicast session. The protocol allows clients to join the multicast session at any point
PXE over DHCP -
WDS uses some of the standard DHCP PXE options (eg. option 54 - ServerId, 252 - WPAD) along with option 250 for exchaning WDS specific options between client and the server.
Looks like currently option 250 is being registered for something else and we will have to come up with a workaround so that option 250 can be used for WDS (if the DHCP packet is a PXE packet) or for what it is being used currently.
Justification for including these parsers -
These parsers aid in debugging WDS issues to a great deal. Also, we have a strong case as most of the deployment MVPs ask for the inclusion of these parsers in NetMon.