MultiProtocol Label Switching

1
MultiProtocol Label Switching

• ?????? ??????
• ?????? ???????
• 30 ?????
• ???? - 2001

2
????????? ?????

• ???? 1. ????? ?????????????? MPLS
• ??????? ????????? MPLS
• ????????? ?????????? ?????????? ?????????????
  ??????????????? MPLS NHRP, IP Switching, Tag
  switching
• ???????? ?????? MPLS
• ???????? ??????? ?????????? MPLS ??????????
  ?????????????, ?????????? IP c ATM ? FR,
  ??????????????? ???????, ??????????????? ???
  ???????, ??????????? QoS, VPN, ????? ?????????
  ???????????? ??? ??????????? ???? ????
•  

3
????????? ?????

• ???? 2. ??????????? MPLS, ???????? ?????????? ?
  ?????????
• ?????? ??????????????? ??????????? - FEC
• LSP, LSR, edge LSR
• ????????? ???????????, ?????? ????????? MPLS
• ????????? ????????????
• -       RSVP
• -       LDP
• -       BGP
• ????????? ????????????? ?????????? ??????????
  OSPF ? IS-IS
• ???????? ????? LSP
• ??????? ?????????????? MPLS
•  

4
????????? ?????

• ???? 3. MPLS ??? ????????? ????????????? MPLS
  IGP
• ??????????? FEC
• ??????????????? ????? ? ??????? ????????? LPD
• ??????????? ?????? MPLS ?????? ATM ? FR
• ???????????????? MPLS IGP ? ??????????????? Cisco
•  

5
????????? ?????

• ???? 4. MPLS Traffic Engineering (TE) ? Fast
  ReRouting (FRR)
• ?????????? ????????? OSPF (CSPF)
• ???????????? ? ??????? RSVP ext ? CR-LDP
• ??????? ???????????????? ????? MPLS TE
•  

6
????????? ?????

• ???? 5. ????????? ???????? ???????????? ? ???????
  MPLS
• MPLS DiffServ
• DiffServ Aware MPLS TE
• ??????? AutoBandwidth ???????? Cisco
•  
•  

7
????????? ?????

• ???? 6. MPLS VPN
• ????????????? VPN ?? ?????? ????????? BGP
• MPLS VPN ??? ?????????? ?????????? ??????
•  

8
????????? ?????

• ???? 7. ???????? MPLS - ????????? ????? ? ?????
  SDH ? DWDM (Generalized MPLS)
• ???? GMPLS
• ??????????? GMPLS
• ?????????? RSVP ? CR-LDP ??? ????????? SDH ? DWDM
•  

9
?????? MPLS
 

• ????????? ???????????? ?????????? IP ??????
  ??????????
• ???????? ??? ?????? ?????????? ??????? ?????? ?
  ??????????????
• ????????? ??????????????????? ????????
  ???????????? ??? ?????????? ?????
• ????????? ????? ?????????????????? ????
• ????????? ??????????? ??????? ????? (VPN)

10
?????????? MPLS - ?????????????? ???????
??????????? ??????? ? IP-?????

• ???? ????????????? ??????????
• ???????? ??????????? ????/??????????????????
  ????????????? ?? ??????? ?????? - ????????
  ??????????????? ???? ?????? ?? ?? ?????????? ??
  ???????????? ???????? ????
• ???????? ???????????????? ???????? ?????? -
  ????????????? ????? ???? ????? AS, ?????
  ???????? ??????, ?????? ????
• ??????? ?????????? ??????????, ????????? ????????
  ? ????? ??????????? ?????????? ??????
• ???????? ???????? ?????????????? ????? ????????
  ?????????????

11
???????? ?????? MPLS

• ???????? ??????????? ??????? ?? ???? ??????
  ????????????? ??????????? - ???? ????????
  ???????? (IGP)
• Traffic Engineering ?????? ???????? ? ?????
  ???????????? ????? ?????????????????? ????
• QoS ??? ?????????????? ??????? (??????????
  DiffServ aware ???????????? ? DiffServ
  ????????)
• VPN ???????????? ???????? ??????? ??????
  ?????????, ???????? ????????????
• ?????????????????? ?????????????? ? ???????
  ??????? ?? ????????? ????
• ????????? ????????? ????????? (multicast)
• ?????? ?????????? ? ??? ? FR
• ?????????? ???? ???????????? ????????

12
??????????? ?????????? ? ????????????? ????????
??????? ??????

• ??????? ???????? ?????????? ? ????? ?
  ??????????????
• ??????? ???????? ?????????? ? ????? ?
  ????????????
• ???????? (PVC ? SVC)

13
?????? ?? ????????? ???? ? ????? ? ????????????
????????
???????????? ????? ?? ????????? 101-105
S2
3
2
4
1
3
5
S4
S1
2
2
4
3
1
S3
3
1
4
2
4
1
5
S1
S4
S3
P?? L?? P??? L???
1 101 4 101
1 102 3 102
2 101 4 102
3 102 1 102
4 101 1 101
4 102 2 101
? ? ? ?
P?? L?? P??? L???



P?? L?? P??? L???
1 101 2 101
2 101 1 101
2 102 4 101
3 101 5 101
4 101 2 102
5 101 3 101
14
????? ????? ?????????????? ??? ??????????
??????? ????????????? ?? ??????? ???????????
15
???????????????? ???????? IP ??? ?????? ?????
???? ? ??????????? 2-?? ??????
ATM-??????
????? ??????????? ?????????? IP-????? ?????
?????????? ?? ?????? ????????? ???????
16
???????????????? ???????? IP ??? ?????? ?????
???? ? ??????????? 2-?? ??????
4 ????
17
?????? ????????????? ?????????????? ???????? ?
?????????? ??????? 2 ????????
??????? ???????? ?????????????? R1 ?? ????????
?????? ??????? 192.40.15.4 ????? 201.100.10.10
201.100.10.10
192.40.15.4
R1
??? ???????? ?? ??????? ????????????? R1
?????????? ???????????? ??????
???? ???
195.10.200.0
198.10.203.0
196.10.201.0
197.10.202.0
??? ?????? ?? ?????? ??????????????? ?????????
????? SVC?
202.200.10.10
18
? ????? ??????? ??????? ???????? ?????????????, ?
? ????? ???????????
19
????????? ???????????? ? ???????????????
???????????
??????????????
????????
?????? ?? ??????
?????????
?????? ? ???????????? ?????
??????????
???????? ??? ????????
????????
????? ? ?????????? ??????????? ???????
????????? ?????
20
?????????? ????????? ??????????? ? ?????????? ?
???????????????
??????????
Routing protocol
Routing updatesRIP, OSPF
Routing updates RIP, OSPF
Routing table
IP-forwarding
Interface
Interface
???????? ??????
????????? ??????
???????????
????? ??????????? ???? ??? ??????
21
???? 2. ??????????? MPLS, ???????? ?????????? ?
????????? ??????? ????????? MPLS

• MPLS ????????? ????? ????? ????????? ? ???????
  ???????
• ????????? ??????? ??????????? ???????
• ?????????? ???????????? ??? ?????? ?????
  ??????????? ?????? (2 ???? ??????? ???????, ?
  ??? PNNIQ.2931)

22
??????? ????????? MPLS

• ????????????? ??????? ?????? ?????? ??????????
• IP
• ?????????????? ????? ???????? ?? ????????? ?
  ????????? ????
• ??????????????? ????????? ???? ?? ????????
  ???????
• ????????? ??????????
• ????????
• ???????? ?? ?????? ?????????? ??????? (PVC)

23
???????? ?????? MPLS
Router
LSR3
LER5
LSR2
LER1
LSR4
Router
LSR8
LSR7
LER9
LER6
????? MPLS
Router
Router
24
???????? ?????? MPLS
??? ?????????? ??????, ??? ??? ???????? LER?
Router
LSR3
LER5
LSR2
LER1
LSR4
Router
LSR8
LSR7
LER9
LER6
Router
Router
????? MPLS ??? ??????????? ????? ?????????,
?????????????? MPLS ? ??????????? ??? ?????
???????????????? ?????????
25
???????? ??????? ? ???????????

• LSR (Label Switching Router) ????????????? IP ?
  ?????????? MPLS
• LSP (Label Switching Path) ???? ??????????
  ?????
• Edge LSR (LER) ??????????? LSR ??? ??????-????
  ???? (??????? ? ????????)
• FEC (Forwarding Equivalence Class) ?????
  ??????????????? ???????????

26
FEC (Forwarding Equivalence Class) ?????
??????????????? ???????????

• FEC - ?????? IP-???????, ????????????? ???? ? ??
  ?? ?????????? ? ???????? ???????????????
  (????????????? ???????)
• ??? ??????, ????????????? ? ??????? FEC,
  ???????????? ????? ???? MPLS ?? ??????
  ???????????? ???? LSP

27
FEC (Forwarding Equivalence Class) ?????
??????????????? ???????????

• ????????????? ?????????????? ? LER
• ???????? ???? ????????????? ????????????? LER ?
  ???????????? ? ??????????? ????????, ?????????
  MPLS
• ?????????? ????????????? - ?? ????????? IP-??????
  ?????????? (???????????? ???? hop-by-hop IGP)
• ?????? ???????? ???? - (IP Source, IP
  Destination, Port Source, Port Destination,
  ??????? ?????????)
• ? ???????????? ? ???????????? QoS ??????? ??????
  ??????????
• ? ???????????? ? ???????????? VPN -
  ?????????????? ? ???????????? VPN ???????
• ?? ????? ??????????? ???? ?????? IP-?????????
  (RTP) ?? ?????????? ????

28
FEC (Forwarding Equivalence Class) ?????
??????????????? ???????????

• ????? ???????? ??????? ? ?????????????? ?????? ?
  ????????????? ?????? FEC, ?????? ???????????
  ????? Label ? ????? ?????????? ?????????? ?
  ?????? MPLS ?? ?????? ??????? ??????, ??? ???
  ???????????? ?? ?????? ? ???? ?? ???? ??????
  ??????!
• ???????????? ??????? ??????????? MPLS ??
  ????????? ?? ??????????? ???????????? IP ??
  ?????? ??????????
• ????? ????????? ?????? ??????? ?? ?????????,
  ??????????? ??????? IP-?????????????
• ?????????, ? ???????? ??????? ?????
• LER, ??????? ??????? ????? ? ?????? LER ?????
  ???????????? ?????? ???? ??? ??????????? ???????
  ? ?????? ? ???? ?? ?????????? ? ??????????
• LER ??????? ????? ???????? ???? explicit rout
• ??????? ????????? ? ???????????????? ???????????
  ?????? ? LER

29
????? (labels) MPLS
Label 20 ??? CoS (Experimental), 3 ???? S
??? ????? ?????, 1??? TTL Time to live, 8 ???

• ???????? ????? ???????? ???? ????????? MPLS ?
  ????? Ethertypes/PPP PIDs/LLC/SNAP ? ??.
• ??????????? ????????????? ? ????? ?????? ?????
  ??? ????? ????? ???? ?????
• MPLS LSRs always forward packets based on the
  value of the label at the top of the stack

30
??????? ?????
PPP Header(Packet over SONET/SDH)
PPP Header
Layer 3 Header
Shim Header
Ethernet Hdr
Layer 3 Header
Shim Header
Ethernet
FR Hdr
Layer 3 Header
Shim Header
Frame Relay
HEC
DATA
CLP
PTI
VCI
GFC
VPI
Shim H
ATM Cell Header
Label
Shim H
HEC
DATA
CLP
PTI
VCI
GFC
VPI
Subsequent cells
31
?????? ?????? MPLS ? FR
0 1
(Octets) ----------------------
------------------------ (Octets)0

/ Q.922 Address
/ / (length 'n'
equals 2 or 4) /

----------------------------------------------
n .
/
. / /
MPLS packet /
.
--------------------------
--------------------
7 6 5 4 3 2 1
0 (bit order)
----------------------------------------
(octet) 0 DLCI(high order)
0 0 -----------------------
----------------- 1 DLCI(low
order) 0 0 0 1
----------------------------------------
DLCI Label, Shim ?????????
????? ?????
32
?????????????? ?????????? LER
(1).???? ?????????????? ??????????
????????? ????????????? ?????? ????????? ??????
- OSPF, IS-IS
????????? ????????????? ???? ???????? ???????
Traffic Engineering, QoS, VPN
(2).????? ?????
????????? ???????????? LDP, CR-LDP, RSVP, BGP
(3).????????? ????
(4).??????????? ????? ?????????????? ????
???? ?????????? ?? ?????? ??????? NHLFE
33
1. ???? ? ??????????????? ?????????? ? ?????????
? ????????? ????????? ????

• ?????????????? ?????????? ? ?????????? ??????
  ???????????? ????????? ?????
• ???????????? ??? ?????? ????? ??????? ? ????
• ?????? LSR ? LER ?????? ???????? ??????????? ?
• ????????? ????
• ????????? ??????? ? ?????? LSR
• ??????????????/???
• ?????????? ??????????? (Traffic Engineering)
• ????????????? (????? ??????? ? ?.?.) (Traffic
  Engineering)

34

• ??????????? ???????????? ???????????
  ????????????? ?????????? (? ??????????? ?? ????
  ?????? MPLS)
• IS-IS - ?????????????? ???? TLV (Type Length
  Value)
• OSPF - Opaque LSA

LSR3
LER5
LSR2
LER1
LSR4
Router
LSR8
LSR7
LER9
LER6
Router
Router
Link LSR7-LER6 State up Bandwidth
155 Unreserved 103
35
?????????????? ???? LSR
34/12
10/3
3
5
34/8
1
2
10/3
4
10/5
34/10
9
8
155/103
7
10/5
34/10
155/45
6
36

• 2. ????? ?????
• ???? ??????????? ???????????????????
  ??????????????? LSR 1-3-5-8
• ??????????? ?? ????????? ?????????????? ????
• ????? ???? ?????????? ??????? (??????????) ???
  ????????????? (???????????) ??????? ?????? ????,
  ??????????????? ?????? ??????????? ?????? (IGP,
  TE, VPN, QoS)
• ?????????????? ???? ????? ???????????????, ????
  ????? ???????????????? MPLS-??????
• ????????? ?????????? ????? ???????????? ???
  ????????? ?????

37
?????? ?????? ??? ?????? TE
????? ????????? ???? ?? 1 ? 6 ??? ?????? ?
????????? ????????? 4 ????/?
34/12
10/8
10/5
3
5
10/6
34/8
1
2
10/5
4
34/20
34/20
20/8
34/20
34/20
10/5
34/8
34/3
34/20
9
8
155/103
7
10/5
34/3
155/45
6
???? LSP 1-2-8-4-7-6
38
???? ????? LSP (Label Switching Path)
1. Hop-by-hop route - ?????? LSR ????????? ????
??????????, ??? ??? ?????? ??????
IP-?????????????? ??? ?????????? ?????????????.
????? ???????? IGP-????? 2. Explicit route -
????? ???? (????????????? ?? ?????????) ??????????
? ????????????? LER ????????? ????, ??????? ?????
??????????????? ? ???? ????? ???? - ??????
?????????? ??? ??????? ?????? ????? Traffic
Engineering ? QoS ????? ???? ????? ???? ?????
?????? (strict) ??? ???????? (loose)
39
??????? ? ????????? ????? ????
34/12
10/8
10/5
3
5
10/6
34/8
1
2
10/5
4
34/20
34/20
20/8
34/20
34/20
10/5
34/8
34/3
34/20
9
8
155/103
7
10/5
34/3
155/45
6
??????? (strict) ???? LSP 1-2-8-4-7-6 ?????????
(loose) ???? 1-7-6 ??? ?????????? ???? ?????
???????? LSR?
40

• ????? ?????? ???? ????? ???? ??????
• ??????????? (on-line)
• ?????????? (off-line)

??????????? - ? ??????? Constrained Routing
Protocol (????????, OSPF ? ???????????? - CSPF)
????????????? ???????? ?????? ????????? ????? ?
????????????? ????? ??????? ??????? ?????????? -
?????? ??????????? ? ?????????????, ??????????
???????? ??????? ? LER
41
3. ????????????
???????? ???????????? - ???????? ?????????????
????? (Label Distribution Protocol) - ????????

• ???????? ???????????? ????????? ???
• ??????????? ??????????????? LSR ????? ???? ?
  ????????????? ????????? ?????
• ???????????? ???????? ????? ????? ???
  ?????????? ? ?????? ? ???? ?? ???? ? ?????? LSR
• ?????????? MPLS ????????? ????????????? ?????????
  ?????????? ????????????
• LDP (Label Distribution Protocol) - ???????????
  ???????? ??? MPLS IGP
• ?????????? RSVP Traffic Engineering
• CR-LDP - ?????????? LDP - Traffic Engineering
• ?????????? BGP - VPN

42
??????????? ????
201
3
5
1
2
4
217
Ingress LER
146
156
9
8
Egress LER
7
6
null
????? ????????????? ? ???????? ??????? ??
?????????? LSR (egress LER) ? ??????? (ingress
LER) Downstream assigned
43
?????? ?? ????
LSR9
LSR7
LSR3

• ??? LSR9 ???????????? ??????, ????????????? ????
  192.100.0.0/16 ?? IGP
• LSR7 downstream neighbour
• LSR3 upstream neighbour

192.100.0.0/16
??????? LSR ?????? ?? ?????????? ?????????????
????? (????????????) MPLS, ??? MPLS IGP
downstream neighbour ??? Next Hop
44
?????????????? ? ???????????? ?????
LSR9
LSR7
LSR3
L 123
FEC 192.100.0.0/16 L 123 ????????
LSR9 Outgoing label ??? LSR3 Incoming label ???
LSR9
45
?????? ????????????? ?????

• Downstream On Demand - ????????????? ?? ???????.
  Downstream LSR ???????? ?????? ?? Upstream LSR ?
  ????????? ????? ???????????? FEC
• Downstream Unsolicited - ????????????? ???
  ??????? ? ?????????? ???????????. Downstream LSR
  ????????? ????? FEC ??? ???????????????? ???????
  ? ???????? ?? Upstream LSR.

????? ?????? ??????? ?? ??????, ???????? MPLS
(IGP, Traffic Engineering ? ?.?.)
46
?????? ?????????? ?????????????? ?????

• 2 ?????? (mode) ?????????? ??????????????
• ??????????? - Independent Label Distribution
  Control
• ?????? LSR ????? ????????? ?????????? ?
  ??????????????? ?????, ?? ????????? ?????????
  ????? ?? ??????????? LSR - ??????, ???
  ??????????? ?????? ???????? (?? ?????????
  ?????????????)
• - ??? ?????? Downstream On Demand - ??
  ?????????, ????? ?????????? LSR ??????? ?? ??????
• - ??? ?????? Downstream Unsolicited - ? ?????
  ??????, ????? ?????? LSR ????? ???????? ?
  ???????? ????? ? FEC
• ????????????? - Ordered Label Distribution
  Control
• ?????? ??????? ?????????? ????? ????? ??????
  ????????? LSR ?? ???? (egress LSR)
• ??????????? ??? Constraint-based Routing - ????
  ?????????? ?? ?????? ?? ?????? ??????????

47
??????? LSR ????????? ??? ?????? ??????????
????????????? ?????
??????? FEC-To-NHLFE, FTN
???????? FEC ?????
123.20.0.0 255.255.0.0 106
194.20.0.0 255.255.255.0 107
???????????? ? ingress LER ??? ????????????
???????, ??????? ????? ???????? ??? ????????
????? ???? LSP
48
??????? LSR ????????? ??? ?????? ??????????
????????????? ?????
??????? ??????????? Next Hop Label Forwarding
Entry (NHLFE)
??????? ???? ??????? ????? Next Hop(????, MAC) ????????(??????? ?????, ??????? ?????, ???????? ?????)
Serial 1 - Serial 1 Push 245
Serial 1 - Serial 2 Pop
Serial 2 106 Serial 3 Swap 107
49
????????? ?????? ? NHLF ??? ????? ?????
??????? ???? ??????? ????? Next Hop(????, MAC) ????????(??????? ?????, ??????? ?????, ???????? ?????)
Serial 1 106 Serial 1 Swap 215
Serial 1 106 Serial 2 Swap 345
Serial 1 106 Serial 3 Swap 124
???? ?????? ????????, ??????????????????
50
??????
????? ?? ???? ????? ? ???????? Next Hop ??? ??
LSR, ??????? ????????? ??????????? ?????? ??
?????? ??????
??? ?????? ????? ????????? ????? ???????? ?????
?????? ??? ????
51
4. ??????????? ???????

• ?????????? ?? ?????? ??????? ??????????? ?????
  ?????? FTN ? NHFLE
• ??? ????? ? ????? MPLS ?????? LSR (LER) ?????????
  ????????? Shim ????? ??????????? ?????????? ?
  ???????? ?????? ? ????????? ?????? ????? ??
  ??????? FTN
• ????????? IP-?????? ?? ????????????? ?
  ????????????? LSR
• ??? ?????? ?? ?????? MPLS ???????? LSR ???????
  Shim-????????? ? ?????????? ????? ?? ??????
  IP-??????

52
?????????????? ????? LSR
???? ?????? ???? Traffic Engineering
IGP-????? ????????
???????????? RSVP
???? ?????????????? ??????????Traffic Engineering
??????????? ???? ?????????????? ??????????
???????????? LDP
???? ? ??????????????? ??????????.
????????? ????????????? OSPF, IS-IS, BGP
IP
??????? ????????-?????
???? ??????????? IP
??????? NHLFE
IP(FEC)
???? ??????????? MPLS
53
????????????? ?????? ????? ???? LSP
????????????? LSR (penultimate LSR) ????? 1.
????????? ???????? swap null (???????? ?? ???.)
2. ??? ???????? pop ?????? ????? ?????? egress
LSR
54
??????
????? ??????? ????????? ?????????????? LSR
???????????????? ??? ????????? ????????
????????????
55
??????
??? ?????? ?????? LSR, ???? ??????? ????? ?
??????, ??????? ??? ?? ? ????? ?????? NHFLE?
56
???? TTL

• ??????????
• ?????? ? ????????????? ? ??????
• ??????????? ??????? ???????? ?????? (scope),
  ????????, ??? ????????? ???????

• ????? ????????? ?????? ? ?????? ????????????
  ????????? MPLS-??????
• PPP, Ethernet
• ??? ??? ? FR ???????????? ?????? ???? ?
  ????????? ATM/FR ???!

57
?????? ? ????????????? ??????? ? ???????
MPLS-ATM/FR
?????? LSR ?????? non-TTL ????????? ????????????
???????? ?????? ?? ???? ?????? ? ????? ?
??????????? ?????, ???? ?????????? ?????
??????????? ?????? ??? ????? TTL ?? ????????
?????? ???? ????? ??????, ??? ???????? TTL, ??
???????????? ????????? TTL ?? ?????????? ????? ?
????? ???????????? downstream LSR. ?????? TTL
?? ????????? ????????? ????????????? ?????