Page 1 of 50
Ethernet over MPLS
2001.7.25
미디어링크 선행개발팀
손 장 우
son@netmanias.com
016-460-5747
Analyze Trends, Technologies and Market
NETMANIAS WHITE PAPER
Ethernet over MPLS
by 손장우
07/25/2001
손장우
son@netmanias.com
www.netmanias.com
016-460-5747
NETMANIAS-SON-38Page 2 of 50
Contents
• Metro Bottleneck: Problems are …
• Ethernet Invasion
• Metro Ethernet Evolution
• VLAN-based Ethernet VPN service
• EoMPLS-based Ethernet VPN service
• End-to-end Ethernet over MPLS service
• ConclusionPage 3 of 50
Internet Performance
병목구간은 ?
Backbone Metro
CO CO
LAN
Residentia
l
Metro
- nDS0, T1, T3 Leased line
(64K, 256K, 516K, 1.544M,
2.048M, 45M)
- TDM-based SONET
Enterprise
GE 도입 Æ Fast (Gigabit)
backbone
IP/DWDM, TSR
OADM, OXC, OPS
Residential  Æ Fast (Gigabit/Terabit)
Cable, xDSL, and
Broadband Wireless
Æ Fast (Mbps/user)
Contents
User User
Global Internet
or Other ISP
Metro  
POP
Metro  
POPPage 4 of 50
MAN service
Backbone Metro
CO CO
LAN
Residential
Metro
Contents
(localization)
Web server, Co-location,
ASP, CSP, DBSP
Global Internet
or Other ISP
Metro  
POP
Metro  
POP
- nDS0, T1, T3 Leased line
(64K, 256K, 516K, 1.544M,
2.048M, 45M)
- TDM-based SONET
LAN-to-LAN
interconnection
Internet Access
xSP AccessPage 5 of 50
그렇다면,
현재 MAN ?
• 현재, Business Internet access, private line은 SONET/SDH 기반 전송
망을 이용하는 데, 이 SONET/SDH망의 문제는
– Circuit switching/TDM, BW allocation flexibility, Expensive
– Upgrade ?, Long lead time
OC3/12
access
ring
OC3/12
access
ring
OC12/48
Metro Core Ring
OC3/12
access
ring OC12/48
Metro Core Ring
OC3/12
access
ring OC3/12
access
ring
OC12/48
Metro Core Ring
OC3/12
access
ring
OC3/12
access
ring
Long-haul DWDM backbone
(OC48/192)
T1
T3
ISP
POP
지사
본사
Co-location
서울
광주
CO 부산
CO
CO
CO
CO
CO
CO CO
POP
POP
Internet 전용회선
B-to-B 전용회선
512K
OC3/12
access
ring
OC3/12
access
ring
OC12/48
Metro Core Ring
OC3/12
access
ring OC12/48
Metro Core Ring
OC3/12
access
ring OC3/12
access
ring
OC12/48
Metro Core Ring
OC3/12
access
ring
OC3/12
access
ring
Long-haul DWDM backbone
(OC48/192)
T1
T3
ISP
POP
지사
본사
Co-location
서울
광주
CO 부산
CO
CO
CO
CO
CO
CO CO
POP
POP
Internet 전용회선
B-to-B 전용회선
512KPage 6 of 50
Trends
TDM-based SONET
Ethernet over dark fiber
Ethernet & TDM over SONET
Ethernet over SONET
Ethernet over MPLS
IP
Ethernet
Pkt muxing
TDM muxing
Voice
SONET framing
l
IP
PPP/
HDLC/FR
TDM muxing (VT)
Voice
SONET framing
l
IP
Ethernet/VLAN
Dark fiber/l
IP
Ethernet
MPLS
Ethernet/VLAN
Dark fiber/l
IP
Ethernet
GFP, LAPS, PPP/HDLC, SDL, BCP
SONET framing
l
Appian
Lucent
Native networks
Cisco
Redback
Ciena
Riverstone
Extreme
Foundry
Cisco
Nortel
Metro Optical Ethernet
Next Generation SONETPage 7 of 50
Ethernet vs. SONET
• Scalable in increments from  
1M bit/sec to 1G bit/sec and
soon to 10G bit/sec.
• Lower equipment costs.
• Versatile — can support IP  
services.
• QoS issues exist.
• Ethernet is not optimized for
voice traffic.
• Is not quickly restored in the
event of a failure.
Ethernet
• Survivable — 50 msec
restoration.
• 99.999% reliability.
• Optimized for voice traffic.
• Billions of dollars worth of
deployed infrastructure.
• Expensive to deploy.
• Is not proficient in carrying
data traffic.
SONETPage 8 of 50
Ethernet Invasion
• LAN = Ethernet
• Customer Premise and Metro optical
Ethernet access
– Legacy expensive Router with TDM
WAN interface(T1/T3)
– CSU/DCU
– SONET ADM
• Metro Core
• National-wide ConsiderationsPage 9 of 50
Ethernet Invasion
LAN
Metro Core
LAN
LAN
LAN
LAN
LAN
WAN
Metro access
Metro access
Metro Core
LAN
Metro Core
LAN
LAN
LAN
LAN
LAN
WAN
Metro access
Metro access
Metro Core
LAN
Metro Core
LAN
LAN
LAN
LAN
LAN
WAN
Metro access
Metro access
Metro Core
LAN
Metro Core
LAN
LAN
LAN
LAN
LAN
WAN
Metro access
Metro access
Metro Core
Ethernet
WDMPage 10 of 50
Metro Optical Ethernet
• Metro Optical Ethernet
– No ATM and/or SONET gear required !
– Optical IP/Ethernet-based network (Fiber to the MTU/Customer)
– Ethernet packet-switching Network (L2/L3)
– Rate-limiting/guaranteeing service: 1M,2M,… ,100M,110,… 1000Mbps
– Dynamic, Real-time, web-based and self-BW provisioning
– Cost-effective (망구축 및 운영 비용)
– Low service charge: $1000/100Mbps/Month (Cogent)
– Target service: LAN-interconnection, Internet access, xSP access
• Advantages
– Cheap
– Easy to maintain and operate
– Statistical multiplexing (cf. SONET)
– Seamless Internetworking (No protocol conversion)
– Scalability (10GbE)
– Fast/Dynamic Provisioning
– BW Granularity(++1M)Page 11 of 50
Metro optical Ethernet
: Evolution
Native Ethernet
(LAN)
• No BW guarantee(CL)
The 1
st Generation
Metro Optical Ethernet
The 2
nd Generation
Metro Optical Ethernet
• No CoS/QoS
• Resiliency
STP (30sec)
•P-to-P, Mesh topologies
•Short range Optics
1000BaseLX (5Km)
• Geographic limitation
Ethernet LAN
• BW guarantee(CO)
= Ingress rate-limiting (UPC)
+ 802.1q VLAN (Connection)
+ 802.1p priority queueing
•Switch architecture
H/W-based wire-speed L2/L3
forwarding, queueing and scheduling
• CoS/QoS
Diff-serv to 802.1p mapping
• Resiliency/Restoration
RSTP/EAPS (1sec)
• Ring topology
• Long range optics (70~150Km)
BGIC/CWDM
•Geographic limitation
Ethernet MAN
• 1 Gigabit Ethernet/4GbE
• Real-time provisioning
• Usage-based billing
•End-to-end BW guarantee(CO)
= Ingress rate-limiting (UPC)
+ MPLS LSP
(Per-LSP BW reservation)
•Switch architecture
H/W-based wire-speed MPLS
forwarding, queueing and scheduling
•MPLS CoS/QoS
802.1p/TOS/Diff-serv/port #
to Exp/CoS or LSP
• Resiliency/Restoration
MPLS fast reroute (100msec)
• Ring: RPR (802.17)
- SRP
- Restoration (<50msec)
- Fair ring -access
- Statistical BW sharing
• Long range optics
BGIC/CWDM/DWDM
• Geographic limitation
Ethernet WAN
• 10 Gigabit Ethernet/40GbE
• Real-time/Web-based/
Self-provisioning
• VoIP
• Usage-based billing
2000
2001-Page 12 of 50
Concept of BW guarantee of
VLAN-based Ethernet VPN (TLS)
MTU MTU
MAC
D
Metro Core
Ethernet Network
a End-to-end connection: 802.1q VLAN
cAt Ingress Point,
Multi-Field Packet Classification
(check L2/L3/L4 header)
-> Rate-limiting/Guaranteeing
-> 802.1p priority mapping
e Priority queueing: 802.1p
Ethernet Switch of SP
Router of Customer
Ethernet Switch of CustomerPage 13 of 50
a End-to-end Connection
: 802.1q VLAN
MTU MTU
MAC   VLAN ID  port
B          7             a
D          5             a
VLAN ID 7
VLAN ID 5
•One VLAN per customer
•VLAN across MAN
- Statically pre-configured, or
- Automatically provisioned
using GARP/GVRP
MAC   VLAN ID  port
B          7             c
D          5             c
a b
MAC   VLAN ID  port
B          7             c
D          5             d
c
d
MAC   VLAN ID  port
D          5            f
MAC
D
MAC
B
MAC   VLAN ID  port
B          7            e
e
f
MAC   VLAN ID  port
D          5            i
MAC   VLAN ID  port
B          7            g
g
i
MAC   VLAN ID  port
D          5            j
j
Forwarding based-on
{dst MAC addr. + VLAN ID}
Metro Ethernet NetworkPage 14 of 50
MTU MTU
MAC   VLAN ID  port
B          7             a
D          5             a
VLAN ID 7
VLAN ID 5
•One VLAN per customer
•VLAN across MAN
- Statically pre-configured, or
- Automatically provisioned
using GARP/GVRP
MAC   VLAN ID  port
B          7             c
D          5             c
a b
MAC   VLAN ID  port
B          7             c
D          5             d
c
d
MAC   VLAN ID  port
D          5            f
MAC
D
MAC
B
MAC   VLAN ID  port
B          7            e
e
f
MAC   VLAN ID  port
D          5            i
MAC   VLAN ID  port
B          7            g
g
i
MAC   VLAN ID  port
D          5            j
j
Forwarding based-on
{dst MAC addr. + VLAN ID}
Metro Ethernet Network
A B
7 A B
7 A B
7 A B
A B
C D
5 C D
5 C D 5 C D 5 C D 5 C D
C D
a End-to-end Connection
: 802.1q VLANPage 15 of 50
c Multi-Field Packet Classification
at Ingress point
MTU a b MTU
c
d
MAC
D
MAC
B
e
f
g
i
j
Metro Core
Ethernet Network
At Ingress Point,
Multi-Field Packet Classification
(check L2/L3/L4 header)
- Rate-limiting/Guaranteeing
(Customer-based/application based)
- 802.1p priority mapping
8B 6B 6B 2B 1B 1B 4B 4B 2B 2B 4B
Ethernet(L2) IP (L3) TDP/UDP (L4)
Pre
dst
MAC
src
MAC
Type
0x0800
CRC
dst
IP
Protocol
ID
src port
number
User
data
TOS
src
IP
dst port
number
8B 6B 6B 2B 1B 1B 4B 4B 2B 2B 4B
Pre
dst
MAC
src
MAC
Type
0x0800
CRC
dst
IP
Protocol
ID
src port
number
User
data
TOS
src
IP
dst port
number
802.1
p/q tag
2B
Type
0x8100
2BPage 16 of 50
Multi-Field packet
Classification
Control packets
Customer A + Voice flows
Customer B + FTP flows
Customer A + E-mail flows
Multi-Field Packet
Classification
Policy priority
queues
8B 6B 6B 2B 1B 1B 4B 4B 2B 2B 4B
Ethernet(L2) IP (L3) TDP/UDP (L4)
Pre
dst
MAC
src
MAC
Type
0x0800
CRC
dst
IP
Protocol
ID
src port
number
User
data
TOS
src
IP
dst port
number
Packet FilterPage 17 of 50
Multi-Field packet
Classification
MAC
IP
0800
IPX
8138
RARP
8035
ARP
0806
VLAN Tag
1800
UDP
17
TCP
06
RSVP
46
IGMP
02
ICMP
01
Telnet
23
HTTP
80
FTP
20
SMTP
25
DNS
53
RTP
5004
a c e
a
8B 6B 6B 2B 1B 1B 4B 4B 2B 2B 4B
Ethernet(L2) IP (L3) TDP/UDP (L4)
Pre
dst
MAC
src
MAC
Type
0x0800
CRC
dst
IP
Protocol
ID
src port
number
User
data
TOS
src
IP
dst port
number
e e
cPage 18 of 50
Ingress Rate Limiting
MTU a b MTU
c
d
MAC
D
e
f i
j
Metro Core
Ethernet Network
Physical port speed 100Mbps
Up
5 Mbps
5 Mbps
Down
Customer
A
5 Mbps
15 Mbps
Customer
B
15 Mbps
15 Mbps
Customer
C
MAN port
GbE
PRL (Port Rate Limiting)
Customer에게 물리적인 port
는 FE이나 GE port를 주고
customer가 사용가능한 BW
를 임의로 조절해줄 수 있는 기
능Page 19 of 50
Ingress Rate Limiting
ARL (Aggregate Rate Limiting)
a 특정 customer로부터 온(그 customer로 갈) aggregate traffic의 rate을 제한(보장)
c 특정 customer의 트래픽 중 특정 응용의 aggregate traffic의 rate을 제한(보장) (예, 회
사 A로부터 유입되는 VoIP aggregate traffic= 1Mbps로 제한/보장해줌 )
Packet Filter
10
Mbps
1Mbps
( )
Traffics from
Customer A
(순간적으로 15Mbps) Voice aggregate traffic
Shaped Traffics from
Medialincs
(Total: 10Mbps
VoIP: 1Mbps)
8B 6B 6B 2B 1B 1B 4B 4B 2B 2B 4B
Ethernet(L2) IP (L3) TDP/UDP (L4)
Pre
dst
MAC
src
MAC
Type
0x0800
CRC
dst
IP
Protocol
ID
src port
number
User
data
TOS
src
IP
dst port
numberPage 20 of 50
Mapping to 802.1p
MTU a b MTU
c
d
MAC
D
e
f i
j
Metro Core
Ethernet Network
MTU a b MTU
c
d
MAC
D
e
f i
j
Metro Core
Ethernet Network
8B 6B 6B 2B 1B 1B 4B 4B 2B 2B 4B
Ethernet(L2) IP (L3) TDP/UDP (L4)
Pre
dst
MAC
src
MAC
Type
0x0800
CRC
dst
IP
Protocol
ID
src port
number
User
data
TOS
src
IP
dst port
number
8B 6B 6B 2B 1B 1B 4B 4B 2B 2B 4B
Pre
dst
MAC
src
MAC
Type
0x0800
CRC
dst
IP
Protocol
ID
src port
number
User
data
TOS
src
IP
dst port
number
802.1
p/q tag
2B
Type
0x8100
2B
Policy
TPI
0x8100
Priority CFI VLAN ID
16 b 3 b 1  b 12 b
Port srcMAC dstMAC TOS srcIP       dstIP      srcPort# dstPort#  VLAN ID  priority
#1   mac_a  mac_b  7   165.132/16  165.154/16   x        y         7          1
802.1p/q header
Classification
At Ingress Point,
8B 6B 6B 2B 1B 1B 4B 4B 2B 2B 4B
Ethernet(L2) IP (L3) TDP/UDP (L4)
Pre
dst
MAC
src
MAC
Type
0x0800
CRC
dst
IP
Protocol
ID
src port
number
User
data
TOS
src
IP
dst port
number
8B 6B 6B 2B 1B 1B 4B 4B 2B 2B 4B
Pre
dst
MAC
src
MAC
Type
0x0800
CRC
dst
IP
Protocol
ID
src port
number
User
data
TOS
src
IP
dst port
number
802.1
p/q tag
2B
Type
0x8100
2B
Policy
TPI
0x8100
Priority CFI VLAN ID
TPI
0x8100
Priority CFI VLAN ID
16 b 3 b 1  b 12 b
Port srcMAC dstMAC TOS srcIP       dstIP      srcPort# dstPort#  VLAN ID  priority
#1   mac_a  mac_b  7   165.132/16  165.154/16   x        y         7          1
802.1p/q header
Classification
At Ingress Point,Page 21 of 50
e Priority queueing and
scheduling
MTU a b MTU
c
d
MAC
D
MAC
B
e
f
g
i
j
Metro Core
Ethernet Network
Priority
Field
체크
Highest Priority
Lowest Priority
Priority Field(802.1p bits)
1 7 A B
3 5 CD
1 7 A B
3 5 CD 3 5 CD
1 7 A B
A B
CD
1 7 A B
3 5 CD
802.1q tag (VLAN ID)
802.1p tag (priority)Page 22 of 50
Concept of BW guarantee of
VLAN-based Ethernet VPN (TLS)
MTU MTU
MAC
D
Metro Core
Ethernet Network
a End-to-end connection: 802.1q VLAN
cAt Ingress Point,
Multi-Field Packet Classification
(check L2/L3/L4 header)
-> Rate-limiting/Guaranteeing
-> 802.1p priority mapping
e Priority queueing: 802.1p
Ethernet Switch of SP
Router of Customer
Ethernet Switch of Customer
1 7 A B
A B
A B
802.1p/q Page 23 of 50
L4 prioritization
VLAN ID 7
VLAN ID 5
A B
CD
Ethernet frame
MTU Last mile Metro core Last mile MTU
802.1p/q Network
Lookup: {dst MAC addr. + VLAN ID}
Queueing: check 802.1p tag
Output link scheduling:
Priority scheduling based on 802.1p tag
1 7 A B
2 5CD
A B
CD
1 7 A B
2 5CD
1 7 A B
2 5CD
1 7 A B
2 5CD
Classification:
port , L2 MAC addr., IP addr., TOS/DSCP,
PID, TCP/UDP Port number
Policy/ACL
Rate-limiting
802.1q VLAN tagging
802.1p priority marking based-on TOS/DSCP, Port#
1 7 A B
2 5CD
802.1q (VLAN ID)
802.1p (priority)
8B 6B 6B 2B 1B 1B 4B 4B 2B 2B 4B
Ethernet(L2) IP (L3) TDP/UDP (L4)
Pre
dst
MAC
src
MAC
Type
0x0800
CRC
dst
IP
Protocol
ID
src port
number
User
data
TOS
src
IP
dst port
number
8B 6B 6B 2B 1B 1B 4B 4B 2B 2B 4B
Pre
dst
MAC
src
MAC
Type
0x0800
CRC
dst
IP
Protocol
ID
src port
number
User
data
TOS
src
IP
dst port
number
802.1
p/q tag
2B
Type
0x8100
2B
Application 별 서비스 차별화 가능Page 24 of 50
Problem of VLAN-based
TLS service
• VLAN space limitation: 4096 VLANs (VLAN
ID=12bits)
• MAC address limitation
• No Bandwidth reservation in metro core (end-toend)
• No traffic engineering in metro core (STP Path)
• Slow restoration time(STP, RSTP, EAPS)Page 25 of 50
VLAN space
limitation ~ 4096
MTU MTU
LAN
Metro Core
Ethernet Network
802.1q network
LAN
LAN
LAN
LAN
MTU
LAN
LAN
MTU
LAN
LAN
LAN LAN
LAN LAN
VLAN 4096Page 26 of 50
Supported MAC address
limitation
MTU MTU
LAN
Metro Core
Ethernet Network
802.1q network
LAN
LAN
LAN
LAN
MTU
LAN
LAN
MTU
LAN
LAN
LAN LAN
LAN LAN
Metro Core Ethernet Switches must learn
MAC addresses of
1) Customer router, if  CPE = L3
2) Individual machine, if CPE = L2Page 27 of 50
No Traffic
Engineering
MTU MTU
LAN
Metro Core
Ethernet Network
802.1q network
LAN
LAN
LAN
LAN
MTU
LAN
LAN
MTU
LAN
LAN
LAN LAN
LAN LAN
Not Traffic-Engineered Path
(Path determined by STP)
VLAN 100’’s PathPage 28 of 50
No end-to-end
BW guarantee
MTU MTU
LAN
Metro Core
Ethernet Network
802.1q network
LAN
LAN
LAN
LAN
MTU
LAN
LAN
MTU
LAN
LAN
LAN LAN
LAN LAN
VLAN 100’’s Path
No BW reservation for VLAN’s connection in Metro Core
No BW guarantee in Metro Core
Only provide priority queueing (802.1p)Page 29 of 50
No End-to-end
BW reservation
BW shared by 3 VLAN traffics:
No BW guarantee in metro core trunk link
Priority queueing: 802.1p
200M
500M
500M
700M
500M
500M
1200M
VLAN A
VLAN B
VLAN C
Ingress rate limitingPage 30 of 50
MPLS in Metro
Optical Ethernet Network
MTU MTU
LAN
Metro Core
Ethernet Network
MPLS network
LAN
LAN
LAN
LAN
MTU
LAN
LAN
MTU
LAN
LAN
LAN LAN
LAN LAN
MPLS
LSP 100
MPLS
LSP 200
MPLS LER/LSR
(MPLS over Ethernet)Page 31 of 50
Ethernet over MPLS
: Martini draft
• Martini Internet draft:
– Encapsulation Methods for Transport of Layer 2 Frames Over MPLS
(draft-martini-l2circuit-encap-mpls-01.txt )
– Transport of Layer 2 Frames Over MPLS
(draft-martini-l2circuit-trans-mpls-05.txt)
• Layer 2 PDU (frame relay, ATM AAL5, Ethernet)를 MPLS Network
을 통해 전달하는 절차(Encapsulation, Level distribution)를 기술
• No IP routing in Provider’s Network (LER/PE and LSR/P)
• Service Provider provides L2 connectivity only
• MPLS-based L2 circuit
• Metro Ethernet에 Martini draft를 적용
Ethernet over MPLS (MPLS over Ethernet) network
(Tunnel LSP, VC LSP, Encapsulation)Page 32 of 50
Tunnel LSP
MTU MTU
LAN
Metro Core
LAN
LAN
LAN
LAN
LAN LAN
T-LSP
100
T-LSP
200
tunnel LSP: LER(PE)간에 설정
- LER로 들어오는 목적지 LER이 같은 모든 VLAN traffic을 Aggregation  
T-LSP
200
LAN LANPage 33 of 50
VC LSP
MTU MTU
LAN
Metro Core
LAN
LAN
LAN
LAN
LAN LAN
T-LSP
100
T-LSP
200
T-LSP
200
LAN LAN
Egress LER, R2
Must know how to treat the received frame
=> Define “VC label (VC LSP)”
R2 can infer form the VC label
the outgoing interface and perhaps the VLAN ID
VC LSP
VC LSP = per VLAN LSP
- Egress LER에서 각각의 VLAN을
Label값만 보고 알 수 있게 해준다.Page 34 of 50
VC LSP setup
MTU MTU
Metro Core
LAN
LAN
LAN
LAN
T-LSP
200
Label mapping msg
VC label(VC label TLV) = 25
VLAN ID(FEC TLV) = 1
configuration
- VLAN 1, port 10
- peer router: 10.0.0.1
VC label = 25
Port VLAN VC lsp T-lsp
11      1       25       200
T-LSP
VC-LSP
VLAN
VC-LSP
VLAN
10.0.0.1 20.0.0.1Page 35 of 50
Frame flow over
MPLS Network
MTU MTU
LAN
Metro Core LAN
LAN
LAN
T-LSP
200
VC-LSP
25
MAC
B
MAC
APage 36 of 50
MTU Access Switch
MTU MTU
Metro Core
LAN
LAN
LAN
LAN
MAC  VLAN ID  outgoing port
B      1 3
L3 PDU
(IP packet)
DA
B
SA
A
E-type
(0x0800)
802.1p/q
(2/1)
DA
B
SA
A
E-type
(0x8100)
E-type
(0x0800)
L3 PDU
(IP packet)
VLAN tagging
3
MAC
B
MAC
A
Ethernet Type
0x0800: IPv4
0x0806: arp
0x8035: rarp
0x8100: vlanPage 37 of 50
Ingress LER
MTU MTU
Metro Core
LAN
LAN
LAN
LAN
4
MAC
B
MAC
A
802.1p/q
(2/1)
DA
B
SA
A
E-type
(0x8100)
E-type
(0x0800)
L3 PDU
(IP packet)
MAC  VLAN ID  outgoing port    Tunnel Label  VC label Label
B           1 4               5        25
1) VLAN-to-LSP mapping (Label
push)
- Tunnel LSP: aggregation LSP
- VC LSP: per-VLAN LSP
2) CoS(Ext) field marking
Classification (802.1p/MFPC)
3) Outer MAC header (MACs of LSRs)
Outer
Ethernet
Header
802.1p/q
(2/1)
DA
B
SA
A
E-type
(0x8100)
E-type
(0x0800)
L3 PDU
(IP packet)
DA
b
SA
a
E-type
(0x8847)
Tunnel
label(5)
VC
label(25)
Label stack Original 802.1q frame
a bPage 38 of 50
LSR
MTU MTU
Metro Core
LAN
LAN
LAN
LAN
3
MAC
B
MAC
A
C
802.1p/q
(2/1)
DA
B
SA
A
E-type
(0x8100)
E-type
(0x0800)
L3 PDU
(IP packet)
DA
d
SA
c
E-type
(0x8847)
Tunnel
label (30)
VC
label (25)
802.1p/q
(2/1)
DA
B
SA
A
E-type
(0x8100)
E-type
(0x0800)
L3 PDU
(IP packet)
DA
b
SA
a
E-type
(0x8847)
Tunnel
label (5)
VC
label (25)
1) Label Swapping: Tunnel Label
2) Rewrite MAC header
Incoming port  Tunnel Label  outgoing port  
Tunnel Label
1           5               3            30
dPage 39 of 50
LSR
MTU MTU
Metro Core
LAN
LAN
LAN
LAN
3
MAC
B
MAC
A
802.1p/q
(2/1)
DA
B
SA
A
E-type
(0x8100)
E-type
(0x0800)
L3 PDU
(IP packet)
DA
f
SA
e
E-type
(0x8847)
VC
label (25)
802.1p/q
(2/1)
DA
B
SA
A
E-type
(0x8100)
E-type
(0x0800)
L3 PDU
(IP packet)
DA
d
SA
c
E-type
(0x8847)
Tunnel
label (30)
VC
label (25)
1) Pop Tunnel label
2) Rewrite MAC header
Incoming port  Tunnel Label  outgoing port
1           5               3
e fPage 40 of 50
Egress LER
MTU MTU
Metro Core
LAN
LAN
LAN
LAN
4
MAC
B
MAC
A
802.1p/q
(2/1)
DA
B
SA
A
E-type
(0x8100)
E-type
(0x0800)
L3 PDU
(IP packet)
802.1p/q
(2/1)
DA
B
SA
A
E-type
(0x8100)
E-type
(0x0800)
L3 PDU
(IP packet)
DA
f
SA
e
E-type
(0x8847)
VC
label (8)
1) Pop VC label
2) Infer from VC label how to
process the original frame
(output port)
Incoming port   VC Label  outgoing port
1           25                          4
Original 802.1q frame
e fPage 41 of 50
Egress LER
MTU MTU
Metro Core
LAN
LAN
LAN
LAN
MAC
B
MAC
A
DA
B
SA
A
E-type
(0x0800)
L3 PDU
(IP packet)
802.1p/q
(2/1)
DA
B
SA
A
E-type
(0x8100)
E-type
(0x0800)
L3 PDU
(IP packet)
MAC  VLAN ID  outgoing port
B        1 1
1Page 42 of 50
Good of MPLS
• VLAN space 문제 해결 (VLAN ID Reuse)
• Metro Core에서 MAC주소수 문제 해결
• Traffic Engineering in Metro Core
• Protection: MPLS Fast Reroute (<100msec)
• MPLS QoS: LSP별로 차별화 또는 Ext/CoS비
트
• MPLS-based Layer 2 VPN
• Scalability
• SecurityPage 43 of 50
VLAN ID Reuse
MTU MTU
LAN
LER
LAN
LAN
LAN
LAN
MTU
LAN
LAN
MTU
LAN
LAN
LAN
LAN
LAN LAN
MPLS
LSP 200
VLAN ID
Reuse
LER
MPLS
LSP 100 LSP 100Page 44 of 50
Local
MAC address
learning
MAC address learning
MTU MTU
LAN
LER
LAN
LAN
LAN
LAN
MTU
LAN
LAN
MTU
LAN
LAN
LAN
LAN
LAN LAN
LER
MAC address
learning ˚
Metro core에서는 customer의 MAC address와 VLAN ID가 노출되지
않는다.
따라서, MAC address를 learning할 필요가 없다.
LER만 LER에 연결된 지역의 customer의 MAC만 learning하면 된다.
802.1q MPLSPage 45 of 50
Traffic Engineering
in Metro Core
MTU MTU
LAN
LER
LAN
LAN
LAN
LAN
MTU
LAN
LAN
MTU
LAN
LAN
LAN
LAN
LAN LAN
LER
Traffic-Engineered
Path Page 46 of 50
Good of MPLS
MTU
LER/PE
LSR/P
LER/PE
LSR/P
VLAN space 문제 해결 (VLAN ID Reuse)
Metro Core에서, 학습해야 할
MAC address수 문제 해결
VLAN
VLAN
VLAN
MPLS
• Traffic Engineering
in Metro Core
• MPLS restoration
- pre-established standby LSP
- Fast Reroute
• MPLS QoS
LSP1
LSP2 LSP3Page 47 of 50
End-to-end Ethernet
over MPLS
Wide Area
MPLS backbone
802.1q
VLAN
802.1q
VLAN
802.1q
VLAN
( MPLS over POS )
Metro
MTU
LER
LER
LER
Metro
Metro
802.1q
VLAN
802.1q
VLAN
MPLS Network
CPE
CPE
CPE
CPE
CPE
CPEPage 48 of 50
MPLS Network
End-to-end Ethernet
over MPLS
Wide Area
MPLS backbone
EoMPLS
802.1q
VLAN
( MPLS over POS )
Metro
MTU LER
LER
LER
Metro
Metro
802.1q
VLAN
802.1q
VLAN LER
LER
LER
EoMPLS
CPE
CPE
CPE
CPE
CPE
CPEPage 49 of 50
Ethernet over
MPLS Solutions
• Riverstone
• Extreme
• Foundry
• Cisco
• NortelPage 50 of 50
Conclusion
• Metro Bottleneck: Problems are …
• Ethernet Invasion
• Metro Ethernet Evolution
• VLAN-based Ethernet VPN service
• EoMPLS-based Ethernet VPN service
• End-to-end Ethernet over MPLS service
• Next-Generation Metro Network
– 10 GbE : BW
– RPR : Restoration
– MPLS : Service creation (VPN, QoS)