A Day in the Life of an L2/L3 TSN Data Packet.

Transcription

1 A ay in the ife of an 2/ N ata Packet. Norman Finn ersion 2 ar., 204 tsn-nfinn-ay-n-he-ife-024-v02.pdf 02 Plenary meeting, Beijing China, arch 204

2 his presentation, tsn-nfinn-ay-n-he-ife- 024-v02 is an annex to a two-part presentation. Part, tsn-nfinn-2-ata-plane-024-v04, introduces concepts on which these presentations depend. Part 2, tsn-nfinn--ata-plane-024-v0, is concerned with ayer issues. ee also cb-nfinn-how-any-ans-024- v02. tsn-nfinn-ay-n-he-ife-024-v02.pdf 2 02 Plenary meeting, Beijing China, arch 204

3 . A very brief introduction, using concepts introduced in the preceding decks, followed by A ay n he ife Of A Packet case studies. 2. Case : nd-to-end equenced N encaps.. Case 2: ixed 2/ Pgram pseudowire encaps. 4. Case : Pgram pseudowire to equenced N titching.. Case 4: C 249- HR or PRP encaps.. Case : nd-to-end thernet-over-xyz tunnels.. Case : P ulticast encaps.. A one-slide summary of conclusions is given. tsn-nfinn-ay-n-he-ife-024-v02.pdf 02 Plenary meeting, Beijing China, arch 204

4 tsn-nfinn-ay-n-he-ife-024-v02.pdf 02 Plenary meeting, Beijing China, arch 204 4

5 Higher ayers 2-ata-Plane Higher ayers work as always. equencing equencing numbers packets, and discards duplicates. plit / erge Circuit ncaps/ecaps plit /erge has one circuit above and two below its layer. Circuit ncaps /ecaps marks individual circuits. tsn-nfinn-ay-n-he-ife-024-v02.pdf 02 Plenary meeting, Beijing China, arch 204

6 2-ata-Plane his is the stack for a bridge that proxies for a non-n client, e.g. Bridge in the following examples: Proxy services bridge baggy pants diagram AN AC PHY Bridge relay N ncaps/ecaps plit/erge equencing Circuit etection AN AC 2 PHY 2 tsn-nfinn-ay-n-he-ife-024-v02.pdf 02 Plenary meeting, Beijing China, arch 204

7 equenced N tagging tsn-nfinn-ay-n-he-ife-024-v02.pdf 02 Plenary meeting, Beijing China, arch 204

8 op-down view tsn-nfinn-ay-n-he-ife-024-v02.pdf 02 Plenary meeting, Beijing China, arch 204

9 N tagging 2 4 Given that introduction, let us examine the simplest case: end-to-end connectivity through a Bridged AN. tsn-nfinn-ay-n-he-ife-024-v02.pdf 9 02 Plenary meeting, Beijing China, arch 204

10 N tagging 2 4 alker is N-aware, istener is not. alker is not AN-aware, istener is ANaware. tsn-nfinn-ay-n-he-ife-024-v02.pdf 0 02 Plenary meeting, Beijing China, arch 204

11 2 4 Without N, the bridges bridge. A: istener A: alker : whatever data A: istener A: alker AN 0 : whatever data tsn-nfinn-ay-n-he-ife-024-v02.pdf 02 Plenary meeting, Beijing China, arch 204

12 2 4 alker and istener have a higher layer relationship. A: istener A: alker : whatever data A: istener A: alker AN 0 : whatever data tsn-nfinn-ay-n-he-ife-024-v02.pdf 2 02 Plenary meeting, Beijing China, arch 204

13 2 4 he operator wants alker and istener to have a N circuit relationship,, (4[99]) so that they can get the N o. (he bridges need the circuit in order to provide the N o.) A: istener A: alker circuit_ : whatever data A: N 4 A: AN tag 99 : whatever data A: istener A: alker AN 0 : whatever data tsn-nfinn-ay-n-he-ife-024-v02.pdf 02 Plenary meeting, Beijing China, arch 204

14 2 4 But, the istener is N-unaware, so Bridge has to provide the N Circuit ecaps as a proxy service. A: istener A: alker circuit_ : whatever data A: N 4 A: AN tag 99 : whatever data A: istener A: alker AN 0 : whatever data tsn-nfinn-ay-n-he-ife-024-v02.pdf 4 02 Plenary meeting, Beijing China, arch 204

15 2 4 he operator wants equencing proxied for and by Router and Bridge, and seq. ecaps. A: N 4 A: istener A: istener A: alker circuit_ : whatever data A: N 4 A: AN tag 99 : whatever data A: AN tag 99 : N eq equence # : whatever data A: alker AN 0 circuit_ seq_number : whatever data A: istener : whatever data A: alker AN 0 tsn-nfinn-ay-n-he-ife-024-v02.pdf 02 Plenary meeting, Beijing China, arch 204

16 2 4 We want plit and erge functions, for seamless redundancy where the circuit bifurcates. A: N 40 A: N 2 A: A: A: A: A: istener A: N 4 A: alker A: AN tag 2 : N eq AN tag 0 : N eq vlan_ 0 circuit_ A: A: circuit_ AN tag 99 equence # equence # equence # AN 0 : whatever : whatever : whatever : whatever : whatever : whatever data data data data data data tsn-nfinn-ay-n-he-ife-024-v02.pdf 02 Plenary meeting, Beijing China, arch 204

17 Why is this N ecaps function upside down? Because it peers with alker s N ncaps function. tsn-nfinn-ay-n-he-ife-024-v02.pdf 02 Plenary meeting, Beijing China, arch 204

18 higher layers Host proxy 02. Relay 02. Relay Host proxy higher layers N e AN AC circuit- sequenceaware relay eq q N e plit N d N e AN AN AN AN AC virtual AC AC AN AC circuit- sequenceaware relay eq v N d erge N d AN AN AN virtual AC AC AN AC alker Bridge Bridge istener his is a more accurate picture, but you can only get so much information on one slide. tsn-nfinn-ay-n-he-ife-024-v02.pdf 02 Plenary meeting, Beijing China, arch 204

19 Higher ayers Circuit ncaps n this example, the Circuit ncaps is in the alker system (above the link). Circuit ecaps equencing plit Circuit ncaps And the equencing is in Bridge (below the link). tsn-nfinn-ay-n-he-ife-024-v02.pdf 9 02 Plenary meeting, Beijing China, arch 204

20 Higher ayers n this example, the istener system is Nunaware. equencing erge Circuit ecaps And the equencing, erge, and N ecaps are all in Bridge (below the link). tsn-nfinn-ay-n-he-ife-024-v02.pdf Plenary meeting, Beijing China, arch 204

21 ay-in-the-life view tsn-nfinn-ay-n-he-ife-024-v02.pdf 2 02 Plenary meeting, Beijing China, arch 204

22 equenced N tagging 2 4 A: A: circuit_identifier : P Pgram alker s stack is not ANaware. his is what the frame is when it hits the N ncaps layer. Note that Bridge would normally add a AN 0 tag to this frame. tsn-nfinn-ay-n-he-ife-024-v02.pdf Plenary meeting, Beijing China, arch 204

23 equenced N tagging 2 4 A: N 4 A: AN tag 99 : P Pgram alker is N-aware, so the N ncaps layer adds a AN tag, even though alker s stack is not ANaware. alker could add sequence number, but doesn t. tsn-nfinn-ay-n-he-ife-024-v02.pdf 2 02 Plenary meeting, Beijing China, arch 204

24 equenced N tagging 2 4 A: A: circuit_identifier 4[99] vlan_identifier 0 sequence_number : whatever data he equencing function adds a new N sequence number. (Notionally, the A/AN have been restored. n practice, one would not bother.) tsn-nfinn-ay-n-he-ife-024-v02.pdf Plenary meeting, Beijing China, arch 204

25 equenced N tagging 2 4 A: A: circuit_identifier 4[99] vlan_identifier 0 : N eq equence # : whatever data he equencing encaps function replaces the sequence_number parameter with a new N sequence number tag, to be defined by 02.. tsn-nfinn-ay-n-he-ife-024-v02.pdf 2 02 Plenary meeting, Beijing China, arch 204

26 equenced N tagging 2 4 A: A: circuit_ 40[2] or 2[0] vlan_identifier 0 : N eq equence # : whatever data he plit function creates two packets, with different circuit_identifiers. tsn-nfinn-ay-n-he-ife-024-v02.pdf 2 02 Plenary meeting, Beijing China, arch 204

27 equenced N tagging 2 4 A: N 40 A: AN tag 2 : N eq equence # : whatever data After being encoded, again, this is the thernet frame on the upper path. tsn-nfinn-ay-n-he-ife-024-v02.pdf 2 02 Plenary meeting, Beijing China, arch 204

28 equenced N tagging 2 4 A: N 2 A: AN tag 0 : N eq equence # : whatever data Note that we have a different circuit on the second path. Another presentation is required to discuss whether the A, the AN, both, or neither, should be different. tsn-nfinn-ay-n-he-ife-024-v02.pdf 2 02 Plenary meeting, Beijing China, arch 204

29 equenced N tagging 2 4 A: A: circuit_ 40[2] or 2[0] vlan_identifier : N eq 0 : equence N eq # : equence whatever # : whatever data data he N ecaps function restores the proper A and AN, and extracts the circuit_identifier. tsn-nfinn-ay-n-he-ife-024-v02.pdf Plenary meeting, Beijing China, arch 204

30 equenced N tagging 2 4 A: A: circuit_identifier 4[99] vlan_identifier 0 : N eq equence # : whatever data he erge function takes all packets and gives them the same circuit_identifier. (t is the same as on the alker to Bridge link.) (here are still 2 packets.) tsn-nfinn-ay-n-he-ife-024-v02.pdf 0 02 Plenary meeting, Beijing China, arch 204

31 equenced N tagging 2 4 A: A: circuit_identifier 4[99] vlan_identifier 0 sequence_number : whatever data he equencing ecapsulation function exposes the sequence_ number so that the equence iscard function can discard the duplicates. (here are still 2 packets.) tsn-nfinn-ay-n-he-ife-024-v02.pdf 02 Plenary meeting, Beijing China, arch 204

32 equenced N tagging 2 4 A: A: AN tag 0 : whatever data A single frame is output from equencing function. t is what would have come from the alker, modulo the AN tag changes the bridges would make. tsn-nfinn-ay-n-he-ife-024-v02.pdf 2 02 Plenary meeting, Beijing China, arch 204

33 ummary: 2 4 his uses the full plit/erge functionality with different cicuit_identifiers on the paths. A: istener A: alker circuit_ : whatever data A: N 4 A: AN tag 99 : whatever data A: N 40 A: AN tag 2 : N eq equence # : whatever data A: N 2 A: AN tag 0 : N eq equence # : whatever data A: A: : whatever data AN 0 tsn-nfinn-ay-n-he-ife-024-v02.pdf 02 Plenary meeting, Beijing China, arch 204

34 ariant : 2 4 his uses the full plit/erge functionality with different cicuit_identifiers on the paths. A: istener A: alker circuit_ : whatever data A: N 4 A: AN tag 99 : whatever data A: N 4 A: AN tag 99 : N eq equence # : whatever data A: A: : whatever data AN 0 tsn-nfinn-ay-n-he-ife-024-v02.pdf 4 02 Plenary meeting, Beijing China, arch 204

35 ariant 2: 2 4 f alker does the sequencing and encaps, and all paths use the same encaps, it gets really simple! A: N 4 A: istener A: alker circuit_ : whatever data A: AN tag 99 : N eq equence # : whatever data A: A: : whatever data AN 0 tsn-nfinn-ay-n-he-ife-024-v02.pdf 02 Plenary meeting, Beijing China, arch 204

36 tsn-nfinn-ay-n-he-ife-024-v02.pdf 02 Plenary meeting, Beijing China, arch 204

37 2 Bridge 4 R/router N aware alker Router plit R R / Router R / Router Bridges Bridge erge N unaware istener ingle-port N- AN-aware alker and a single-port N- AN-unaware istener. he alker sequences, and peers to the iscard in Bridge. alker attached to a router; istener to a bridge. A network with a variety of routers and bridges. tsn-nfinn-ay-n-he-ife-024-v02.pdf 02 Plenary meeting, Beijing China, arch 204

38 2 Bridge 4 R/router pseudowire label 2 control (sequence) Pgram alker and Bridge have chosen to use an Pgram pseudowire for the circuit. tsn-nfinn-ay-n-he-ife-024-v02.pdf 02 Plenary meeting, Beijing China, arch 204

39 2 Bridge 4 R/router N aware alker Router plit R R / Router R / Router Bridges Bridge erge Router and Bridge are the split/merge (seamless redundancy) peers, because they split and merge the circuits. N unaware istener (nserting the plit function in Router requires an extra ncode/ecode pair.) tsn-nfinn-ay-n-he-ife-024-v02.pdf 9 02 Plenary meeting, Beijing China, arch 204

40 2 Bridge 4 R/router N aware alker Router plit R R / Router R / Router Bridges Bridge erge N unaware istener Assuming that the encode/decode used by the plit/erge are pseudowires, we require a network of abel witched Paths (Ps) to connect to to. ach endpoint is a abel dge Router (R) function. tsn-nfinn-ay-n-he-ife-024-v02.pdf Plenary meeting, Beijing China, arch 204

41 2 Bridge 4 R/router N aware alker N Circuit ncaps/ecaps pairs are needed to convey the circuit over the various Bridged ANs. (Note the blue, instead of purple, letter and outline.) Router plit R R / Router R / Router Bridges Bridge erge N unaware istener tsn-nfinn-ay-n-he-ife-024-v02.pdf 4 02 Plenary meeting, Beijing China, arch 204

42 tsn-nfinn-ay-n-he-ife-024-v02.pdf Plenary meeting, Beijing China, arch 204 Pgram pseudowire Pgram alker has an Pgram to send to istener. 2 4

43 Pgram pseudowire 2 4 pseudowire label 2 control (sequence) Pgram alker s combined N ncaps and equencing functions use an Pgram pseudowire for the circuit. Bridge s functions are at the other end of the network. tsn-nfinn-ay-n-he-ife-024-v02.pdf 4 02 Plenary meeting, Beijing China, arch 204

44 Pgram pseudowire 2 4 label 0 pseudowire label 2 control (sequence) Pgram n the general case, the R function would encapsulate the pseudowire would be carried in an P. tsn-nfinn-ay-n-he-ife-024-v02.pdf Plenary meeting, Beijing China, arch 204

45 Pgram pseudowire 2 4 label 0 pseudowire label 2 control (sequence) Pgram n this particular case, we will assume that Router is doing a Penultimate Hop Pop (PHP) function. hat eliminates the need for the outside label encaps. tsn-nfinn-ay-n-he-ife-024-v02.pdf 4 02 Plenary meeting, Beijing China, arch 204

46 he PHP step may be controversial. Perhaps there is another P label, a path label, on the frame between the alker and Router. tsn-nfinn-ay-n-he-ife-024-v02.pdf 4 02 Plenary meeting, Beijing China, arch 204

47 Pgram pseudowire 2 4 A: Router A: : P pseudowire label 2 control (sequence) Pgram o, the frame from alker to Router looks like this on the thernet between alker and Router. tsn-nfinn-ay-n-he-ife-024-v02.pdf 4 02 Plenary meeting, Beijing China, arch 204

48 Pgram pseudowire 2 4 circuit_ (psw 2) sequence_# (control) Pgram he plitter function Router is given the Pgram. in tsn-nfinn-ay-n-he-ife-024-v02.pdf 4 02 Plenary meeting, Beijing China, arch 204

49 Pgram pseudowire 2 4 circuit_ (psw 49) sequence_# (control) Pgram circuit_ (psw ) sequence_# (control) Pgram he plitter function has split the one pseudowire 2 into two pseudowires 49 and, copying the one control word to both of them. tsn-nfinn-ay-n-he-ife-024-v02.pdf Plenary meeting, Beijing China, arch 204

50 Pgram pseudowire 2 4 pseudowire label 49 control (sequence) Pgram pseudowire label control (sequence) Pgram he N ncapsulation function (an Pgram pseudowire encaps) generates these two packets, ready to enter the two Ps. tsn-nfinn-ay-n-he-ife-024-v02.pdf 0 02 Plenary meeting, Beijing China, arch 204

51 Pgram pseudowire 2 4 A: Router 4 A: Router vlan_identifier circuit_identifier : P unnel label pseudowire label 49 control (sequence) Pgram he upper tunnel looks like this, when labeled with unnel, and before applying the N ncapsulation. his would be the usual thernet frame from Router to Router 4 tsn-nfinn-ay-n-he-ife-024-v02.pdf 02 Plenary meeting, Beijing China, arch 204

52 Pgram pseudowire 2 4 A: N 40 A: Router AN tag 09 : P unnel label pseudowire label 49 control (sequence) Pgram But, Router and Router 4 are separated by a N bridged network, so require a N encapsulation. his gets the packet to Router 4. tsn-nfinn-ay-n-he-ife-024-v02.pdf 2 02 Plenary meeting, Beijing China, arch 204

53 Pgram pseudowire 2 4 A: Router A: Router : P unnel label pseudowire label control (sequence) Pgram eanwhile, Router/R, Router/R and Router/R are moving the second P packet along. No N encaps is needed in the absence of bridges. tsn-nfinn-ay-n-he-ife-024-v02.pdf 02 Plenary meeting, Beijing China, arch 204

54 Pgram pseudowire 2 4 A: Router A: Router : P unnel label 4 pseudowire label control (sequence) Pgram eanwhile, Router/R, Router/R and Router/R are moving the P packet along. Router/R changes the unnel label 4. tsn-nfinn-ay-n-he-ife-024-v02.pdf 4 02 Plenary meeting, Beijing China, arch 204

55 Pgram pseudowire 2 4 unnel label pseudowire label 49 control (sequence) Pgram After N decapsulation, Router 4 has this labeled packet. unnel label 4 pseudowire label control (sequence) Pgram And Router has this one. tsn-nfinn-ay-n-he-ife-024-v02.pdf 02 Plenary meeting, Beijing China, arch 204

56 Pgram pseudowire 2 4 pseudowire label 49 control (sequence) Pgram pseudowire label control (sequence) Pgram For the sake of reduced frame size, Router/Ps 4 and perform PHP, which eliminates unnel labels and 4 (and the Rs in Bridge ). tsn-nfinn-ay-n-he-ife-024-v02.pdf 02 Plenary meeting, Beijing China, arch 204

57 Pgram pseudowire 2 4 One can argue the semantics of the green tunnels. n theory, each tunnel continues to its natural end at Bridge. he control plane may maintain this. But, in the data plane, the tunnel label disappears. o, we will shorten the tunnel in the diagram to match the data plane encapsulation tsn-nfinn-ay-n-he-ife-024-v02.pdf 02 Plenary meeting, Beijing China, arch 204

58 Pgram pseudowire 2 4 A: istener A: Router 4 vlan_identifier 0 Router 4 prepares this thernet frame to transmit the pseudowire packet. : P pseudowire label 49 control (sequence) Pgram tsn-nfinn-ay-n-he-ife-024-v02.pdf 02 Plenary meeting, Beijing China, arch 204

59 A: N 994 A: Router 4 AN tag pseudowire label 49 control (sequence) Pgram Pgram pseudowire 2 4 And Router 4 s N ncaps function produces this. tsn-nfinn-ay-n-he-ife-024-v02.pdf 9 02 Plenary meeting, Beijing China, arch 204

60 Pgram pseudowire 2 4 A: N 200 A: Router AN tag pseudowire label control (sequence) And Pgram pseudowire label is translated by Router s N ncaps into this. Pgram tsn-nfinn-ay-n-he-ife-024-v02.pdf 0 02 Plenary meeting, Beijing China, arch 204

61 Pgram pseudowire A: istener A: Router 4 or vlan_identifier 0 circ_ 994[] or 200[] pseudowire label 49 control (sequence) Pgram 2 4 he N ecaps function exposes the pseudowire and restores the thernet frame parameters. tsn-nfinn-ay-n-he-ife-024-v02.pdf 02 Plenary meeting, Beijing China, arch 204

62 Pgram pseudowire A: istener A: Router 4 or vlan_identifier 0 circuit_ psw 49 or sequence_number : P Pgram 2 4 he erge function has to operate on the circuit and sequence number after the pseudowire ecaps function makes these parameters available (and adds the P therype). tsn-nfinn-ay-n-he-ife-024-v02.pdf 2 02 Plenary meeting, Beijing China, arch 204

63 Pgram pseudowire 2 4 A: istener Output from erge function A: Router 4 or vlan_identifier 0 circuit_ psw 2 sequence_number : P Pgram Pseudowire labels 49 and have been combined into the original pseudowire label 2. here are still two packets! tsn-nfinn-ay-n-he-ife-024-v02.pdf 02 Plenary meeting, Beijing China, arch 204

64 Pgram pseudowire 2 4 A: istener A: Router 4 vlan_identifier 0 circuit_ psw 2 sequence_number : P Pgram he equencing iscard function then deletes the redundant frames, passing whichever (from Router 4, in this case) happens to arrive, first. tsn-nfinn-ay-n-he-ife-024-v02.pdf 4 02 Plenary meeting, Beijing China, arch 204

65 Pgram pseudowire 2 4 A: A: Router 4 AN tag 0 : P Pgram When the frame is put on the wire to istener, the circuit_identifier and sequence_number are discarded, and the remaining parameters make the frame. tsn-nfinn-ay-n-he-ife-024-v02.pdf 02 Plenary meeting, Beijing China, arch 204

66 UARY: 2 4 A: N 40 A: Router A: Router A: Router AN tag 09 A: Router A: N 994 A: : P : P A: Router 4 A: istener : P unnel unnel 4 AN tag A: Router 4 Pseudowire 2 Pseudowire 449 Pseudowire Pseudowire 49 AN tag 0 control (seq) control (seq) control (seq) control (seq) : P Pgram Pgram Pgram Pgram Pgram tsn-nfinn-ay-n-he-ife-024-v02.pdf 02 Plenary meeting, Beijing China, arch 204

67 ariant : 2 4 A: N 40 A: Router A: Router A: Router AN tag 09 A: Router A: N 994 A: : P : P A: Router 4 A: istener : P unnel unnel 4 AN tag A: Router 4 Pseudowire 2 Pseudowire 2 Pseudowire 2 Pseudowire 2 AN tag 0 control (seq) control (seq) control (seq) control (seq) : P Pgram Pgram Pgram Pgram Pgram tsn-nfinn-ay-n-he-ife-024-v02.pdf 02 Plenary meeting, Beijing China, arch 204

68 ariant : 2 4 Note that the plit function is still present, in this case, because pseudowire duplication is not a function that is built into the data plane. t does not create new pseudowire labels, though. But, the erge function is now a no-op. tsn-nfinn-ay-n-he-ife-024-v02.pdf 02 Plenary meeting, Beijing China, arch 204

69 tsn-nfinn-ay-n-he-ife-024-v02.pdf 02 Plenary meeting, Beijing China, arch 204 9

70 2 4 gnoring the lower layers, for a moment, we have the pair in alker peering with the pair in Bridge. tsn-nfinn-ay-n-he-ife-024-v02.pdf 0 02 Plenary meeting, Beijing China, arch 204

71 2 4 pseudowire label 49 control (sequence) Pgram n the left-hand world, we want the Circuit ncaps/ecaps to be an Pgram pseudowire, because it is the natural format for a router. tsn-nfinn-ay-n-he-ife-024-v02.pdf 02 Plenary meeting, Beijing China, arch 204

72 2 4 n the right-hand world, we want the Circuit ncaps/ecaps to be the erialized N encaps, because it is the natural format for a Bridge. A: N 40 A: Router 4 AN tag 2 : N eq equence # : P Pgram tsn-nfinn-ay-n-he-ife-024-v02.pdf 2 02 Plenary meeting, Beijing China, arch 204

73 2 W 4 W pseudowire label 49 control (sequence) Pgram An nterworking function carries the equence number across the gap. W A: N 40 A: Router 4 AN tag 2 : N eq equence # : P Pgram tsn-nfinn-ay-n-he-ife-024-v02.pdf 02 Plenary meeting, Beijing China, arch 204

74 2 W 4 W he nterworking Functions W enable the N Pseudowire ncaps function and the equenced N ecaps function at the very ends of the network to be peers, just like the equenced N and Pgram pseudowire end-to-end cases. tsn-nfinn-ay-n-he-ife-024-v02.pdf 4 02 Plenary meeting, Beijing China, arch 204

75 alker side Higher layers Pseudowire Circuit ncaps/ecaps istener side Higher layers eq N Circuit ncaps/ecaps We have two differet protocol stacks, pseudowire and sequenced N, that perform essentially the same function. We want them to peer with each other. tsn-nfinn-ay-n-he-ife-024-v02.pdf 02 Plenary meeting, Beijing China, arch 204

76 alker side Higher layers equencing Pseudowire Circuit ncaps/ecaps istener side Higher layers equencing eq N Circuit ncaps/ecaps Note that we are not including the sublayers that act on the sequence numbers. tsn-nfinn-ay-n-he-ife-024-v02.pdf 02 Plenary meeting, Beijing China, arch 204

77 alker side istener side equence- and Circuit-aware Relay Pseudowire Circuit ncaps/ecaps eq N Circuit ncaps/ecaps f we connect these two stacks with a trivial two-port relay that carries the sequence_number and circuit_identifier parameters intact,... tsn-nfinn-ay-n-he-ife-024-v02.pdf 02 Plenary meeting, Beijing China, arch 204

78 Pseudowire / equenced N nterworking function alker side istener side equence- and Circuit-aware Relay W Pseudowire Circuit ncaps/ecaps eq N Circuit ncaps/ecaps... we have an interworking function. We ll show the interworking relay as W, and the whole interworking function as W. tsn-nfinn-ay-n-he-ife-024-v02.pdf 02 Plenary meeting, Beijing China, arch 204

79 P Pseudo / N titching 2 4 Returning to our previous discussion, we were peering Pgram pseudowire encapsulations at both ends. tsn-nfinn-ay-n-he-ife-024-v02.pdf 9 02 Plenary meeting, Beijing China, arch 204

80 P Pseudo / N titching 2 4 On the right hand side, we eliminate the simple N encaps used to carry the pseudowire, and replace the Pgram pseudowire encaps with the equenced N enaps that we want. tsn-nfinn-ay-n-he-ife-024-v02.pdf 0 02 Plenary meeting, Beijing China, arch 204

81 P Pseudo / N titching 2 4 On the left hand side, we supply termination for the Pgram pseudowire encaps used by alker. tsn-nfinn-ay-n-he-ife-024-v02.pdf 02 Plenary meeting, Beijing China, arch 204

82 P Pseudo / N titching W 2 4 W When we add the interworking relay W,the Pgram pseudowire / equenced N titching nterworking Function W cements the gap. tsn-nfinn-ay-n-he-ife-024-v02.pdf 2 02 Plenary meeting, Beijing China, arch 204

83 P Pseudo / N titching W 2 4 W pseudowire label 49 control (sequence) Pgram pseudowire label control (sequence) Pgram At this point in the end-toend Pgram pseudowire description, we had the naked pseudowire packets in Routers 4 and. tsn-nfinn-ay-n-he-ife-024-v02.pdf 02 Plenary meeting, Beijing China, arch 204

84 P Pseudo / N titching 2 W 4 W circuit_ 49/40[2] sequence_number Pgram hese packets are decapsulated. circuit_ /2[0] sequence_number Pgram tsn-nfinn-ay-n-he-ife-024-v02.pdf 4 02 Plenary meeting, Beijing China, arch 204

85 P Pseudo / N titching A: N 40 A: Router 4 AN tag 2 : N eq equence # W 2 4 W And when re-encapsulated by the equenced N ncaps, the packet in Router 4 becomes 40[2]. : P Pgram tsn-nfinn-ay-n-he-ife-024-v02.pdf 02 Plenary meeting, Beijing China, arch 204

86 P Pseudo / N titching A: N 2 A: Router AN tag 0 : N eq equence # : P W 2 4 W And Pgram pseudowire label 4 is translated by Router s nterworking function W into N circuit 2[0]. Pgram tsn-nfinn-ay-n-he-ife-024-v02.pdf 02 Plenary meeting, Beijing China, arch 204

87 A: istener A: Router 4 or vlan_identifier 0 circuit_ 40[2] or 2[0] sequence_number : P Pgram P Pseudo / N titching W 2 4 W he N ecaps function unwraps the circuit_identifier and sequence_number, and restores the thernet frame parameters. tsn-nfinn-ay-n-he-ife-024-v02.pdf 02 Plenary meeting, Beijing China, arch 204

88 P Pseudo / N titching A: istener W 2 4 W Output from erge function A: Router 4 or vlan_identifier 0 circuit_ xyz sequence_number N circuit s 40[2] and 2[0] have been combined, but there are still 2 packets. : P Pgram o Bridge, this is the endto-end circuit from alker. tsn-nfinn-ay-n-he-ife-024-v02.pdf 02 Plenary meeting, Beijing China, arch 204

89 P Pseudo / N titching W 2 4 W A: istener A: Router 4 vlan_identifier 0 : P Pgram he equencing iscard function passes only one of the frames. he circuit_identifier and sequence_number are no longer needed. tsn-nfinn-ay-n-he-ife-024-v02.pdf 9 02 Plenary meeting, Beijing China, arch 204

90 P Pseudo / N titching W 2 4 W A: istener A: Router 4 : P Pgram After discarding the unused parameters and converting the rest to the appropriate frame, this is what is output to istener. tsn-nfinn-ay-n-he-ife-024-v02.pdf Plenary meeting, Beijing China, arch 204

91 UARY: W 2 4 W A: N 40 A: Router A: Router A: N 2 A: Router AN tag 09 A: Router A: Router A: : P : P AN tag 0 : P unnel unnel 4 : N eq A: istener Pseudowire 2 Pseudowire 449 Pseudowire equence # A: Router 4 control (seq) control (seq) control (seq) : P : P Pgram Pgram Pgram Pgram Pgram tsn-nfinn-ay-n-he-ife-024-v02.pdf 9 02 Plenary meeting, Beijing China, arch 204

92 ariant 4: W 2 4 W CRCU A: N 40 A: Router A: Router A: N 2 A: Router AN tag 09 A: Router A: Router A: : P : P AN tag 0 : P unnel unnel 4 : N eq A: istener Pseudowire 2 Pseudowire 2 Pseudowire 2 equence # A: Router 4 control (seq) control (seq) control (seq) : P : P Pgram Pgram Pgram Pgram Pgram tsn-nfinn-ay-n-he-ife-024-v02.pdf Plenary meeting, Beijing China, arch 204

93 ariant : Ω pseudowire label 2 control (sequence) Pgram alker could be dual-homed. n this case, clearly must supply the sequence numbers. he sequence numbers are usually part of the encapsulation. o, terminates the pseudowire, not routers 2 and. tsn-nfinn-ay-n-he-ife-024-v02.pdf 9 02 Plenary meeting, Beijing China, arch 204

94 tsn-nfinn-ay-n-he-ife-024-v02.pdf 02 Plenary meeting, Beijing China, arch

95 HR tagging 2 4 Again, alker is N-aware, istener is not. his time, alker is not AN-aware, istener is AN-aware. n this case, HR and N ncaps and ecaps are combined into a single layer. tsn-nfinn-ay-n-he-ife-024-v02.pdf 9 02 Plenary meeting, Beijing China, arch 204

96 his is not HR. t is the HR format used for a different purpose. his idea may or may not sit well with C CX. his HR-like layer: Connects to a single port, not two. ay use one sequence number variable per circuit, not one per host. (his is debatable.) f the station is AN aware, has the AN tagging below (outside) the HR sublayer. tsn-nfinn-ay-n-he-ife-024-v02.pdf 9 02 Plenary meeting, Beijing China, arch 204

97 host bridge HR Higher ayers equencing Circuit ncaps/ecaps plit / erge Note that this is the layering the top box is alker, and the bottom box is Bridge. HR combines the Circuit ncaps/ecaps and equencing functions. t also encapsulates the destination AC address which, as we will see, is not really very useful. tsn-nfinn-ay-n-he-ife-024-v02.pdf 9 02 Plenary meeting, Beijing China, arch 204

98 HR-like tagging 2 4 A: A: circuit_identifier : P Pgram alker s stack is not ANaware. his is what the frame is when it hits the N ncaps layer. Note that Bridge would normally add a AN 0 tag to this frame. tsn-nfinn-ay-n-he-ife-024-v02.pdf 9 02 Plenary meeting, Beijing China, arch 204

99 HR-like tagging 2 4 A: N 4 A: AN tag 99 HR therype pid, length, sequence A: he equencing and combined HR/N ncaps layer create a sequence number and add a N/HR tag. therype ata tsn-nfinn-ay-n-he-ife-024-v02.pdf Plenary meeting, Beijing China, arch 204

100 HR-like tagging 2 4 A: N 40 A: AN tag 2 HR therype pid, length, sequence A: therype ata he plit function operates on the N header, for the path, and the HR header, for the sequence number. (he pid field includes a path A / path B flag that intended to be different between the two paths. We may or may not follow that usage.) tsn-nfinn-ay-n-he-ife-024-v02.pdf Plenary meeting, Beijing China, arch 204

101 HR-like tagging 2 4 A: N 2 A: AN tag 0 HR therype pid, length, sequence A: therype ata he other path gets a different A and AN tag. Note that the plit function split N 4[99] into N 40[2] and 2[0]. tsn-nfinn-ay-n-he-ife-024-v02.pdf 0 02 Plenary meeting, Beijing China, arch 204

102 HR-like tagging 2 4 A: istener A: alker vlan_identifier 0 circuit_ 40[2] or 2[0] sequence_number he erge function operates on the circuit_identifier exposed by the decapsulation function therype ata tsn-nfinn-ay-n-he-ife-024-v02.pdf Plenary meeting, Beijing China, arch 204

103 HR-like tagging 2 4 A: istener A: alker vlan_identifier 0 circuit_ 4[99] sequence_number therype ata Output from erge function is the original 4[99] tunnel that originated from Bridge. wo packets are present until the equencing iscard function discards one. tsn-nfinn-ay-n-he-ife-024-v02.pdf 0 02 Plenary meeting, Beijing China, arch 204

104 HR-like tagging 2 4 A: A: AN tag 0 : P Pgram And this is delivered on the wire. tsn-nfinn-ay-n-he-ife-024-v02.pdf Plenary meeting, Beijing China, arch 204

105 ummary: 2 4 A: N 4 A: N 40 A: N 2 A: A: A: AN tag 99 AN tag 2 AN tag 0 HR therype pid, length, seq A: therype ata HR therype pid, length, seq A: therype ata HR therype pid, length, pid, sequence length, seq A: therype ata A: A: AN tag 0 : P Pgram tsn-nfinn-ay-n-he-ife-024-v02.pdf 0 02 Plenary meeting, Beijing China, arch 204

106 ariant : Ω pseudowire label 2 control (sequence) Pgram alker could be dual-homed. n this case, clearly must supply the sequence numbers. he sequence numbers are usually part of the encapsulation. o, terminates the pseudowire, not routers 2 and. tsn-nfinn-ay-n-he-ife-024-v02.pdf 0 02 Plenary meeting, Beijing China, arch 204

107 PRP tagging 2 4 A: N 2 A: AN tag 0 therype ata pid, length, sequence HR therype PRP would work similarly. his could be useful to interoperate with existing deployments. A big issue with the PRP trailer is that you can t tell what it s position is in the tag layering. tsn-nfinn-ay-n-he-ife-024-v02.pdf 0 02 Plenary meeting, Beijing China, arch 204

108 ummary: 2 4 A: N 4 A: N 40 A: N 2 A: A: A: AN tag 99 therype ata pid, length, seq HR therype AN tag 2 therype ata pid, length, seq HR therype AN tag 0 therype ata pid, length, seq HR therype A: A: AN tag 0 : P Pgram tsn-nfinn-ay-n-he-ife-024-v02.pdf 0 02 Plenary meeting, Beijing China, arch 204

109 tsn-nfinn-ay-n-he-ife-024-v02.pdf 02 Plenary meeting, Beijing China, arch

110 2 4 You can always create end-to-end encapsulated thernet circuits using, for example, thernet pseudowire and/or PBB- AC-in-AC in the standard ways it s done, today. tsn-nfinn-ay-n-he-ife-024-v02.pdf 0 02 Plenary meeting, Beijing China, arch 204

111 2 4 he catch is that the alker has a separate thernet port per N flow. his is not compatible with a simple P stack; each port needs its own P address. tsn-nfinn-ay-n-he-ife-024-v02.pdf 02 Plenary meeting, Beijing China, arch 204

112 2 4 here are solutions to this classic multihomed P host problem. t would take some effort to make them compatible with our simple o purpose. tsn-nfinn-ay-n-he-ife-024-v02.pdf 2 02 Plenary meeting, Beijing China, arch 204

113 2 4 And, of course, it still begs the question, How are these packet encapsulated? Again, there are many standard answers to that question. tsn-nfinn-ay-n-he-ife-024-v02.pdf 02 Plenary meeting, Beijing China, arch 204

114 tsn-nfinn-ay-n-he-ife-024-v02.pdf 02 Plenary meeting, Beijing China, arch 204 4

115 Assume for a moment that we do not need to transmit multiple copies on different paths, so we do not need the equencing functions. hen, all we need is a per-flow circuit_identifier on every packet, at both 2 and. P ulticast can supply this, even if it cannot supply a sequence number. tsn-nfinn-ay-n-he-ife-024-v02.pdf 02 Plenary meeting, Beijing China, arch 204

116 n general, an P multicast flow is identified by the ulticast P destination address and the (unicast) P source address. here is a 2: mapping of P multicast addresses to AC Group As. tsn-nfinn-ay-n-he-ife-024-v02.pdf 02 Plenary meeting, Beijing China, arch 204

117 f the network administrator and protocols can ensure that the P multicast addresses are unique over the flows, no N encapsulation is necessary. Otherwise, the usual N encapsulation will solve the Bridges problems with multicast, and the Routers can easily identify the streams to apply N o. tsn-nfinn-ay-n-he-ife-024-v02.pdf 02 Plenary meeting, Beijing China, arch 204

118 2 4 he normal P Group address and AN may or may not be sufficient for Bridged N networks, but the N encapsulation fixes this. A: Group Z? A: Group Z A: : P C Pgram A: Router AN tag 09? : P C Pgram A: Group Z? A: Router 4 AN tag 0 : P Pgram tsn-nfinn-ay-n-he-ife-024-v02.pdf 02 Plenary meeting, Beijing China, arch 204

119 And, if the protocol carried in the P ulticast packet has a sequence number, then of course, the P ulticast format is sufficient, in the data plane, for seamless redundancy, as well. tsn-nfinn-ay-n-he-ife-024-v02.pdf 9 02 Plenary meeting, Beijing China, arch 204

120 2 4 he P multicast control protocols, of course, would need work. A: Group Z A: : P C Pgram A: Group Z? A: Router AN tag 09? : P C Pgram A: Group Z? A: Router 4 AN tag 0 : P Pgram tsn-nfinn-ay-n-he-ife-024-v02.pdf Plenary meeting, Beijing China, arch 204

121 tsn-nfinn-ay-n-he-ife-024-v02.pdf 02 Plenary meeting, Beijing China, arch 204 2

122 he layering scheme in tsn-nfinn-2-ata-plane-024-v04 works. here are existing protocols for carrying both all-2 and mixed 2/ N circuits. here are other possibilities for creating N circuits: xan, P, and dozens of as-yet proprietary schemes. A new 02. sequence number tag can handle thernet end-to-end seamless redundancy. ixed 2/ seamless redundancy requires either: electing a single end-to-end 2+ split/merge format (e.g. pseudowire); or An interworking function between and 2 split/merge technologies; or Creating explicit end-to-end thernet tunnels. tsn-nfinn-ay-n-he-ife-024-v02.pdf Plenary meeting, Beijing China, arch 204

123 hank you.