bridging packet walk throughs...n1 n2 n3 n4 p3_0 p1_0 3 bridge fdb bridge c1 p2_1 mac port 4 7...

IEEE Plenary July 2001

Bridging Packet Walk Throughs

Wai-Chau Hui Harry Peng

2IEEE Plenary July 2001

Agenda

• Bridging for 802.17 • Issues• Methods based on Deployed

Networks


Options

1. Transparent bridges2. Encapsulated bridgingEthernet services3. Double encapsulated bridging4. Encapsulated bridge


Customer data Packet

RPR Header

Notes• PRINT THIS DOCUMENT IN COLOR. • Aging of FDB, ARP are not included in these walkthroughs.

Packet Legend

MAC MAC

MAC relay(port state, FDB,

forwarding process)

Higher Layer(bridge protocol,bridge mgmnt)


••1.0 Transparent Bridge 1.0 Transparent Bridge

••2.0 Encapsulated Bridge2.0 Encapsulated Bridge

••3.0 Ethernet Service with 802.17 Bridge3.0 Ethernet Service with 802.17 Bridge



Only .17 stations with Transparent Bridge -1

p2p1N1 N2 N3 N4p3 p1

L

.

N1_P1

MAC

N1 UNI FDB N4 UNI FDB

3

3

Data

Bridge FDB

Bridge

ringN4_P1 N1_P1

R

r/l

N1_P1

MACp2N1_P1

portMAC

47

7 Data

4 Data CRC

CRC

N4_P1 N1_P1

N4_P1 N1_P1

CRC

ring = TTL, COS, Type…

chec

chec

ring chec

ring

Bridge N5 N6

p2p3p2

5

6

5 DataringN4_P1 N1_P1

6 Data CRCN4_P1 N1_P1

CRCchec

ring chec

Bridge FDB

p2N1_P1

portMAC


Only .17 stations with Transparent Bridge -2

R

L

r/l

N4_P1

N1_P1

MAC


8

Data

Bridge FDB

ringN4_P1N1_P1

L

R

r/l

N4_P1

N1_P1

MAC

p2N1_P1

p3

port

N4_P1

MAC

10

Dataring

9 Data CRC

CRC

N4_P1N1_P1

N4_P1N1_P1

CRC

chec

chec

ring chec

p2p1N1 N2 N3 N4p3 p1

12

Bridge FDB

Bridge

p3N4_P1

p2N1_P1

portMAC

118

Bridge N5 N6

p2p3

10

9

DataringN4_P1N1_P112

11 Data CRCN4_P1N1_P1

CRCchec

ring chec


.17 Network with Transparent Bridge

• Bridge ports can run STP• All Hosts MAC address will be in bridge FDB and

needs ring speed processing• NOT SCALABLE when connecting to other LAN

segments. All LAN addresses in bridge FDB.• CRC

– Cannot cut-through and distinguish un-routable packet– Use cHEC

• No flooding on other ringlet ports


Transparent Bridging-1

N4 UNI FDBBridge FDB

P1_1

r/l

C1

MAC

P2_0C1

portMAC

P2_0P1_0N1 N2 N3 N4P3_0 p1_0

3

Bridge FDB

Bridge

P2_1C1

portMAC

4

7

Bridge N5 N6

P2_0P3_0

5

6

T

C1

p2

Bridge FDB

P2C1

portMAC

P1_1

2

2 Data CRCN4 C1

DataringN4 C1 CRCchec3Floods by sending in both directionsTTL terminates

4 Data CRCC1N4 ring chec

DataringN4 C1 CRCchec5

P2_1 P2_1 p1_1P3_1

6 Data CRCC1N4 ring chec

DataringN4 C1 CRCchec7

P3_1


Transparent Bridging-2

N4 UNI FDBBridge FDB

P1_1

r/l

C1

MAC

P2_0C1

P3_1

port

N4

MAC

P2_0P1_0N1 N2 N3 N4P3_0 p1_0

11

Bridge FDB

Core Bridge

P3_0N4

P2_1C1

portMAC

10

7

Core Bridge N5 N6

P2_0P3_0

9

8

T

C1

p2

Bridge FDB

P1_1N4

P2C1

portMAC

P1_1

12

12 Data CRCN4C1

DataringN4C1 CRCchec7

8 Data CRCC1 N4 ring chec


P2_1 P2_1 p1_1

P3_1

10 Data CRCC1 N4 ring chec


P3_1


Transparent Bridging

• To address unicast to broadcast problem*– Unknown address floods by sending in both directions using TTL to

strip– Requires MAC port assignment to identify ring ports

• Still have scalability of MAC address at “core” bridges but 802.1D compliant

*RPR and 802.1D bridging Issues. Yong Kim. May 2001


.17 Network edge Encapsulation+Bridge - 1

p2p1N1 N2 N3

N4p3 p1

N4_P1

17MAC

R

L

.

C2

C1

MAC


3

3

Data

Bridge FDB

Bridge

ringN4_P1 N1_P1

N1_P1

17MAC

R

r/l

C1

MACp2N1_P1

r/lMAC

4

7

5 Dataring

4 Data CRC

CRC

N4_P1 N1_P1

N4_P1 N1_P1

C1

C2

C2 C1

C2 C1

C2 C1

8

8

CRC

Data CRCC2 C1

2 Data CRCC2 C1

2

chec

chec

ring chec

Encapsulation

N5 N6

p2p3

5

Bridge

6

7 Dataring

6 Data CRC

CRC

N4_P1 N1_P1

N4_P1 N1_P1

C2 C1

C2 C1chec

ring chec

Bridge FDB

p2N1_P1

r/lMAC

CRC

CRC

CRC

CRC

CRC

Assume:C2 in FDB.If not then Use bcast


.17 Network edge Encapsulation +Bridge - 2

p1N1 N2 N3 N4 p1

N4_P1

17MAC

R

L

.

C2

C1

MAC


10

14

Data

ring

N1_P1 N4_P1

N1_P1

17MAC

L

R

r/l

C2

C1

MAC

14 Data

ring

11 Data

CRC

CRC

N1_P1 N4_P1

N1_P1 N4_P1

C1

C2

C1 C2

C1 C2

C2 C1

15

9

CRC

Data

CRC

C1 C2

9 Data CRCC1 C2

15

chec

chec

ring chec

p2 p3

Bridge FDB

Bridge

p3N4_P1

p2N1_P1

r/lMAC

13

N5 N6

p2p3

12

Bridge

11

Bridge FDB

p2N1_P1

p3

r/l

N4_P1

MAC

DataN1_P1 N4_P1 ring

13 Data

CRC

N1_P1 N4_P1

C1 C2

C1 C2 CRC

chec

ring chec

12

CRC

CRC

CRC

CRC

CRC


.17 Network edge Encapsulation+Bridge

• Core Bridge ports can run STP– Within encapsulation domain

• All Station MAC address will be in bridge FDB and needs ring speed processing– more SCALABLE– All LAN MAC address is now represented by .17 MAC

• CRC – No longer transparent with ring specific fields: changing TTL– Use cHEC

• No flooding on other ringlet ports


17 Network with edge double encapsulate + Encapsulation Bridge -1

.17MAC

C1

MAC

L

.next


3 Data

Bridge XLT

ringFF N1_P1

N1_P1

.17MAC

C1

MAC

R

r/l

N3_P3

next

N1_P1

next

p2N1_P1

portMAC

7 Dataring

4 Data CRC

CRC

FF N1_P1

FF N3_P3

C2 C1

C2 C1

C2 C1

8

CRC

Data CRCC2 C1

2 Data CRCC2 C1

FF N1_P1

FF N1_P1

chec

chec

Unknown broadcast

p2p1N1 N2 N3

N4p3 p1

3

eBridge

4

7

C1

C2

8

2

Translation and Encapsulation

N5 N6

p2p3

5

eBridge

6

5 Dataring CRCFF N5_P3 C2 C1FF N1_P1 chec

6 Data CRCFF N1_P1 C2 C1

Bridge XLT

N5_P3

next

p2N1_P1

portMAC

Assume:C2 NOT in FDB.then Use bcast

ring chec

checring


.17 Network with edge double encapsulation + eBridge -2

p1N1 N2 N3 N4 p1


10

14

Data

Bridge Port XLT

ring

N3_P3 N4_P1

10

12 Data

ring

11 Data

CRC

CRC

N1_P1 N4_P1

N1_P1 N4_P1

C1

C2

C1 C2

C1 C2

C2 C1

15

9

CRC

Data

CRC

C1 C2

9 Data CRCC1 C2

15

N2_P2

.next

C2

C1

MAC

R

L

.

N4_P1

17MAC

N1_P1

17MAC

C2

C1

MAC

L

R

r/l

N3_P3

next

N1_P1 N4_P1

N1_P1 N6_P2

chec

chec

p2 p3eBridge

13

N5 N6

p2p3

12

eBridge

11

Bridge Port XLT

N6_P2

N1_P1

next

p2N1_P1

p3

r/l

N4_P1

MAC

N4_P1

N5_P3

next

p2N1_P1

p3

r/l

N4_P1

MAC

11 DataN1_P1 N4_P1 C1 C2 CRC

ring12 DataN1_P1 N4_P1 C2 C1 CRCN1_P1 N2_P2 chec

chec

chec

ring

ring


.17 Network with edge double encapsulation

• Bridge ports can run STP• One Station MAC address at ring rate

– SCALABLE– Only bridge traffic is forwarded to MAC relay entity

• Not promiscuous mode

• Translation bridge, FDB and needed at user interface– SCALABLE .17 MAC

• CRC• No broadcast on opposite ring port


Encapsulated + .17T.3 +Bridge - 1

p1 N1 N2 N3 N4 p1

C2

N1 UNI FDBN4 UNI FDB

1 C2 C1

1

Data

C1

3

3

Data


ring

p2 p3

17MAC

L

.

C1

MAC

N3_P3

17MAC

R

r/l

C1

MACN1_P1

MAC

RC1

r/lMAC

MAC

LC1

r/lMAC

N1_P1FF C2 C1

CRC

CRCchec

4

4 DataC2 C1 CRC

4

7

5 Dataring FF N5_P3 C2 C1chec

8

8

DataC2 C1

p2C1

r/lMAC

CRC

CRC

p2 p3

6 6

p2 p3p3 N5 N6

5

N5_P3

MAC

RC1

r/lMACMAC

LC1

r/lMAC

p2C1

r/lMAC

p2

6 DataC2 C1 CRC7 Dataring FF N3_P3 C2 C1chec CRC

N5 UNI FDB

N6 UNI FDB


Encapsulated + .17T.3 +Bridge - 2

p1 N1 N2 N3 N4 p1

C2


9 C1 C2

15

Data

C1

10

14

Data

N2 Bridge Port FDBN3 Bridge Port FDB

ring

p2 p3

N2_P2

MAC

R

L

.

C2

C1

MAC

N3_P3

MAC

L

R

r/l

C2

C1

MACN1_P1

MAC

RC1

L

r/l

C2

MAC

N4_P1

MAC

LC1

R

r/l

C2

MAC

N4_P1N3_P3 C1 C2

CRC

CRCchec

13

11 DataC1 C2 CRC

13

10

12 Dataring N5_P3 N6_P2 C1 C2chec

15

9

DataC1 C2

p2C1

P3

r/l

C2

MAC

CRC

CRC

p2 p3

11 11

p2 p3p3 N5 N6

12

N5_P3

MAC

RC1

L

r/l

C2

MAC

N6_P2

MAC

LC1

R

r/l

C2

MAC

p2C1

P3

r/l

C2

MAC

p2

13 DataC1 C2 CRC14 Dataring N1_P1 N2_P2 C1 C2chec CRC


Remote Bridging

• …..


Conclusion

• 802.17 can work with 802.1D T bridges– MAC address scaling issue.

• Some other options to build a L2 network– Single Encapsulated Bridges– Double Encapsulated Bridges

• Single MAC Address at 802.17 MAC station

– Ethernet Service Use 802.1D bridge• Use 802.3 to 802.17 encapsulation

bridging packet walk throughs...n1 n2 n3 n4 p3_0 p1_0 3 bridge fdb bridge c1 p2_1 mac port 4 7...

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