MPLS Japan - L2 Metro
Future of MPLS L2 VPN
8 November 2002

The Power of PerformanceJune 2002

The Problem… Why MPLS?
• Why do we like MPLS L2 VPN?
• What is MPLS L2 VPN?
• When should we use MPLS L2 VPN?

22002/11/22©2002 Foundry Networks, Inc.

Service Provider Problems…
• Minimum ROI with Legacy Technologies– ATM (ah, seems like only yesterday)– ISDN– Frame Relay– Complexity to Install/Maintain = Higher Cost of Ownership• Few Resources Available– Sluggish Economy– Skilled Engineers• Making Real Profits with Networking Services• BOTTOM Line: How much revenue does my network make?
• Time to spend wisely and be profitable. Take care of business.

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2002/11/22©2002 Foundry Networks, Inc.

Solving the Problems• Centralizing on Fewer Technologies– MPLS (Key NG Technology)– Ethernet (Champion of L2 Technologies)– IPv4 (Champion of L3 Technologies)– IPv6 (Key NG Technology)• Combine Resources– Common Systems = Common Skills = Simplicity =Lower TCO• Profitable Service Planning– Cost of Equipment (per port & per device)4

2002/11/22©2002 Foundry Networks, Inc.

Label Switching• Foundry switches remove the CRC from incoming
Ethernet frames and replaces the 4 bytes with aForwarding ID (FID) inside our box– Removing 4 bytes and adding 4 bytes forconsistency of rate limiting calculations• The FID is how the lookup engine communicates withthe forwarding engine– The forwarding engine makes decisions based upon
the FID• Label Switching a forwarding paradigm
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2002/11/22©2002 Foundry Networks, Inc.

MPLS Drivers for Service Providers• GMPLS– MPLS merges legacy and future technologies• Shim, Native• Generalized packet switching– Multi-Protocol Lamda Switching (MPʎS) O/O/O• Forwarding Speed– Decisions made on labels not MAC type– Theoretically faster (not practically faster today)• VPN’s• Traffic Engineering– QoS– Path Control• Security of Provider Core6

2002/11/22©2002 Foundry Networks, Inc.

Advantages of an MPLS Metro• All Forwarding in MPLS L2 Metro is the same for broadcast,unknown unicast, known unicast, and multicast.

• Separation of Control and Data Planes• MAC addresses not visible in the MPLS core
– No MAC address on MPLS edge with Draft Martini VLL’s– VPLS will have MAC learning on MPLS edge

• Superior Convergence with Fast LSP Fail-over and Switchback(sub-second)– Minimum loss on failure (approx 300ms*)– Immediate switchback (approx 100ms*)* Confirmed by Mier Report on NetIron Metro 1500
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2002/11/22©2002 Foundry Networks, Inc.

The Problem… Why MPLS?
• Why do we like MPLS L2 VPN?
• What is MPLS L2 VPN?
• When should we use MPLS L2 VPN?

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2002/11/22©2002 Foundry Networks, Inc.

L2-VPN Solution 1:
Virtual Leased Line (VLL)
PEPE

VLL 1

VLL 2

Single physicalinterface;
Multiple logical circuits

PE

IXP does not need to learn any customer MAC
anywhere in its network9

2002/11/22©2002 Foundry Networks, Inc.

L2-VPN Solution 2:
Virtual Private LAN Service (VPLS)
IXP network appears
as a single virtual switch
connecting the three sites

PEPE

VC
VC

VC
learning bridge
interconnecting physicalend-points and VC tunnels

PE• IXP network does not need to run any L2 protocol• Customer MAC addresses only need to be kept
at edge devices – avoid large MAC tables in the core10

2002/11/22©2002 Foundry Networks, Inc.

Unique Benefits of L2-VPN• Seamless upgrade from customer’s point of view• Data transport security provided by virtual circuits– Packets for different VPNs are distinct from each other– VPN customer interfaces cannot access IXP devices• Even faster recovery from link/node failure– Active/standby MPLS end-to-end tunnels for rapid fail-over– Fail-over does not result in MAC forwarding DB aging/flushing• Better control of traffic placement in the network– Shortest path forwarding edge to edge
– Options for controlling tunnel placements

L2 topology
11VPLS
2002/11/22©2002 Foundry Networks, Inc.

Unique Benefits of L2-VPN (cont.)• Better traffic engineering and QoS• VLAN-ID translation– Any two ends don’t have to have the same VLAN-ID– More flexibility in VLAN management to customer• Troubleshooting for customer connectivity problem– Diagnosing end-to-end connectivity– MPLS OAM• Flexible intermix of VLL and VPLS solutions

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2002/11/22©2002 Foundry Networks, Inc.

The Problem… Why MPLS?
• Why do we like MPLS L2 VPN?
• What is MPLS L2 VPN?
• When should we use MPLS L2 VPN?

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2002/11/22©2002 Foundry Networks, Inc.

VPLS to Scale End-to-EndLayer 2 Metro4096
ProviderVLANs

L2MetroRegion 1
BigIron 8000

BigIron 4000

4096
User VLANs

BigIron 4000

BigIron 8000

BigIron 4000

BigIron 4000

BigIron 4000

L2Inter-Region
VPLS Metro

L2MetroRegion 2
BigIron 8000

BigIron 8000

BigIron 4000

BigIron 4000

PE

BigIron 4000

L2MetroRegion 3
BigIron 8000

BigIron 4000

BigIron 4000

BigIron 8000

BigIron 4000

BigIron 4000

4096
User VLANs

BigIron 4000

4096
ProviderVLANs

L2MetroRegion 4
BigIron 8000

BigIron 4000

•4096 User VLANS perregion with 802.1Q•4096 provider VLANs
per region with SAV••Solves 4096 VLAN Limit•Efficient L2 Core withMAC scalability•Multi-point VPN
services

BigIron 8000

BigIron 4000

BigIron 4000

Regionalized MAC
tablesCPE
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2002/11/22©2002 Foundry Networks, Inc.

Ethernet vs MPLS
Ethernet

MPLS

Advanced TE

Easy to configure Topology
Groups (802.1s)

Static paths, LSP’s,
OSPF TE, IS-IS TE,RSVP TEHigh Availability

Sub-second failure with link Sub-second resiliency
keep alives and Rapid
with path control
Spanning Tree, Metro Ring
Protocol, or Virtual Switch
Redundancy Protocol (MRPand VSRP are Foundry
Proprietary)Complexity

SimpleAdvanced Expert

Cost ofequipment

Minimum

Maximum

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2002/11/22©2002 Foundry Networks, Inc.

Ethernet vs MPLS and OtherEthernet

MPLS

Additional
Encapsulation
Overhead4 or 8 bytes (VLAN
4 or 8 bytes for labels
and Aggregated VLAN) + DM Encapsulation of
14 bytes (w/o controlword)

Troubleshooting /Accounting /Monitoring

RFC3176 sFlow for
maximum visibility of
all network activities
increasing my network
profitability in a low
cost ASIC

No equivalent yet

Profitability

High

Low Today

Scalability

4,096 VLAN’s

High

MPLS OAM for
Troubleshooting andMonitoring

256 to 1M MAC’s
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2002/11/22©2002 Foundry Networks, Inc.

Metro Router Solutionfor MPLS based MANs
Internet
DataCenters

Internet
Edge (IE)

GigE, 10GigE, SONETand ATMInternet

NetIron 800

NetIron 800
NetIron 800/1500s as
LSR

MTU

NetIron 400
as LER
Customer 1

ProviderEdge (PE)Metro Provider
Core (P)ProviderEdge (PE)Customer 2• Metro VPN support with Draft Martini and VPLS
• Common Sparing and Scalability to 10G

17Customer 1
Customer 2

2002/11/22©2002 Foundry Networks, Inc.

RFC2547 and IP VPN• Complicated– VRF’s, OSPF Downstream bit, Route Tagging, Address
Families, SOO, RT, RD, Route Redistribution PLUS MPLS
protocol suite!
– Lots of room for mistakes (configuration)• Costly (Complexity is directly proportional to cost)• Many organizations will not run routing protocol with the service
provider• Lower performance (more overhead)• More chance for bugs. ALL vendors have bugs. Protocol
Interactions are difficult to troubleshoot• NOT multi-protocol as name implies
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2002/11/22©2002 Foundry Networks, Inc.

Thank You – Questions?

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2002/11/22©2002 Foundry Networks, Inc.