Transcript MPLS-based Virtual Private Networks

MPLS-based Virtual
Private Networks
Khalid Siddiqui
CS 843 Research Paper
Department of Computer Science
Wichita State University
Wichita, KS. 67260
Presentation Outline
To describe the:
 Need
 History
 Working
 Benefits
Of MPLS-based Virtual Private Networks
Why MPLS-based VPNs?
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Trends in Enterprise Computing
1. Companies having offices scattered
throughout the country.
2. On-the-run employees.
Network Congestion
Better QoS required for Voice over IP and
converged voice and data networks.
Security
More sophisticated and costly attacks on networks.
Definition/Features of MPLS
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Stands for Multi-protocol Label Switching.
A technology for speeding up network traffic flow and
making it manageable.
Works by attaching a label in front of each packet.
At each subsequent hop in the network, the router only
takes a look at the label and forwards it.
This is in contrast to the normal switching where routers
look at the IP address of each packet and forward it
accordingly.
This is how MPLS saves time and make traffic flow faster
and smoother.
MPLS Features Contd.
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Label Distribution: Each LSR in the network maintains a
table of {incoming interface, label} and {outgoing
interface, label}.
Resource Reservation: MPLS allows the reservation of
bandwidth beforehand to ensure the continuous
transmission of audio and/or video data.
Traffic Engineering: Process of directing and diverting
traffic to where there are resources available. Factors
that affect Traffic Engineering are:
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Current available resources
Current and future state of the network
QoS Requirements
MPLS Terminology
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Egress: Exit point from the network.
FEC: Forwarding Equivalence Class. A sequence of
packets that are routed the same way, meaning through
the same LSP.
Ingress: Entry point into the network.
LER: Label Edge Router. An LSR at the edge of an
MPLS network. These routers usually make up the
ingress and egress of the network.
LSR: Label Switching Router. A part of the MPLS
network that forwards packets based on the label
attached in front of the packets.
Benefits of MPLS
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Faster Packet Switching.
Better management of different kinds of traffic (voice,
data or converged).
Bandwidth Reservation for different Quality of Service.
Works with Internet Protocol (IP), Asynchronous Transfer
Mode (ATM), Frame Relay; thus multiprotocol.
Expected to work with future technologies.
Definition/Features of VPN
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Stands for Virtual Private Network.
A VPN is a private network that uses a public network
such as the Internet to provide secure remote access to
the corporate network for its employees.
This is in contrast to earlier, expensive leased lines.
It works by sharing the same public infrastructure while
providing security with the help of encryption and
tunneling protocols.
Data (packets) is encrypted by the sender and decrypted
by the receiver.
Only data that is encrypted properly enters a particular
tunnel.
Fig. 2: Virtual Private Network
VPN Terminology
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Tunneling: Transmission of private data through the
public network such that the routing nodes in the network
are unaware that the transmission is part of a private
network.
Encryption: The conversion of data into a form called
ciphertext that is not understandable to anyone who’s
not authorized to look at it.
L2TP: Layer 2 Tunneling Protocol, a common tunneling
protocol.
PPTP: Point to Point Tunneling Protocol, another
common VPN tunneling protocol.
Benefits of VPN
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Extend connectivity of a corporation beyond geographic
boundaries.
Provide secure connections.
Reduce expenditure and costs as compared to leased
lines or WANs.
Eliminate the need for transportation of remote users.
Provide potential for networking in a global environment.
Conclusion
MPLS-based Virtual Private Networks promise a lot of
potential when properly designed.
• Virtual Private Networks provide the highly desirable
benefits of low-cost, high speed, and secure
connection.
• MPLS, on the other hand, provide better Quality of
Service based on Traffic Engineering and Resource
Reservation.
So, I expect to see these kind of networks in heavy
use in the near future.
References
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Brittain, Paul and Adrian Farrel, MPLS Virtual Private Networks,
http://www.dataconnection.com/download/mplsvpns.pdf, November,
2000.
Brittain, Paul and Adrian Farrel, MPLS Traffic Engineering: A choice
of signalling protocols, http://www.dataconnection.com/download/
crldprsvp.pdf, January 17, 2000.
[email protected], MPL VPNs, http://www.ripe.net/ripe/meetings/
archive/ripe-39/presentations/mpls-vpn/, Novermber 2001.
Spirent White Paper, BGP/MPLS Virtual Private Networks:
Performance and Security over the Internet,
http://adtech.spirentcom.com/download/
literatureqqw8/marketingliterature/W5103_RFC_2547.pdf.
Tyson, Jeff, How Virtual Private Networks Work,
http://computer.howstuffworks.com/vpn.htm/printable.