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Packet Pseudowire Encapsulation over an MPLS PSN draft-bryant-pwe3-packet-pw-02.txt. {Stewart Bryant, Sami Boutros, Luca Martini, Siva Sivabalan, George Swallow, David Ward} @ Cisco Systems Andy Malis @ Verizon Communications. Differences 00 to 02.
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Packet Pseudowire Encapsulation over an MPLS PSNdraft-bryant-pwe3-packet-pw-02.txt {Stewart Bryant, Sami Boutros, Luca Martini, Siva Sivabalan, George Swallow, David Ward} @ Cisco Systems Andy Malis @ Verizon Communications
Differences 00 to 02 • Added more detail on forwarding model • Changed from using a PID in CW to a PID label • Included description of PID Label (PIDL) signaling • Added description of FAT label operation • Client Network Layer Model
Packet PW Ref Model Server MPLS PSN PW PW End Service End Service | | |<------- Pseudowire ------->| | | | Server | | |<- PSN Tunnel ->| | | V V | ------- +-----+-----+ +-----+-----+ ------- ) | | | | | | ( client ) | MPLS| PE1 | PW1 | PE2 | MPLS| ( Client MPLS PSN )+ LSR1+............................+ LSR2+( MPLS PSN ) | | | | | | ( ) | | |================| | | ( ------- +-----+-----+ +-----+-----+ -------- ^ ^ | | | | |<---- Emulated Service----->| | | Virtual physical Virtual physical termination termination Client MPLS PSN
Pkt PW Forwarding Model +------------------------------------------------+ | | | +--------+ +--------+ | | | | Pkt +-----+ | | | ------+ +---------+ PW1 +--------+ +------ | | Client | AC +-----+ | Server | | Client | | LSR | | LSR | | Server Network | | | Pkt +-----+ | | | Network ------+ +---------+ PW2 +--------+ +------ | | | AC +-----+ | | | | +--------+ +--------+ | | | +------------------------------------------------+
PID label • Use a label to indicate the PID is more consistent with RFC3031 • A better fit with the MPLS forwarding model • The same as the model proposed from Network Layer Transport Service for MPLS-TP, except that we use LDP signaling for consistency with PWE3.
Label Stack +-------------------------------+ | Client | | Network Layer | | packet | n octets | | +-------------------------------+ | Optional Control Word | 4 octets +-------------------------------+ | PID Label (S=1) | 4 Octets +-------------------------------+ | PW Label | 4 Octets +-------------------------------+ | Server MPLS Tunnel Label(s) | n*4 octets (four octets per label) +-------------------------------+
Packet PW Control Word 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |0 0 0 0| Flags |FRG| Length | Sequence Number | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Now propose the standard (optional) CW
LDP PID FEC Element 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Prot | Reserved | Protocol type | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Protocol Type This 16 bit field contain the protocol type as allocated in the IANA registry "PPP Data Link Layer (DLL) Protocol Numbers"<http://www.iana.org/assignments/ppp-numbers> [RFC1661]. Cannot use interface signaling since we may need to configure new protocols on a running PW (and interface signalling would require us to shut the PW down and withdraw the label) PIDL for a given protocol common to all PWs on a given PE
Finally We would like to make this a WG draft.