MPLS Documentation

1. (MPLS) MultiProtocol Labling
Switching
Software Engineering 4C03
Computer Network & Computer
Security
Dr. Kartik Krishnan
Winter 2004
Final Copy
Researcher: Paul Chan
Student ID: 9914759
Last Revised: March 29th, 2004

2. 4C03 Project Proposal
Objective
As computer networks become more and more a basic staple asset for
both businesses and in general human communication. Since the
adoption of the internet as a main medium of communication, we have
noticed a correlating burden on the existing hardware and software
system supporting these operations. We are beginning to see that our
current IP switching router configurations struggle to satisfy all the
bandwidth and network throughput requirements. In addition with the
growth of online businesses, there is a push for added security measures
to allow for transmission of sensitive data.
MPLS is a hardware and software solution to this problem. By using newer
networking hardware and smarter software algorithms to direct network
data we can achieve more efficient, flexible and secure network
communications.
Approach
In this report we will briefly describe what MPLS is and how it works.
Moreover, we will discuss how MPLS features can improve current
network conditions and lastly we will see an example of how MPLS
impacts current technology. General knowledge about IP based routing
and switching is assumed as we have studied these in our 4C03
Networking & Security course in great detail.
Impact
This report is intended to give this audience a brief introduction in the
developing networking technology due to be released sometime in the
summer of 2004. From this presentation the audience should be able to
gain insight into the growth of network usage and the necessity for more
efficient ways route information. It should be clear that newer technology
is needed to replace the current technology if we wish to continue
supporting increasing numbers of networked users and devices. Hence
the need for new and cleaver ways to do the things we do on a daily basis.
We will show that MPLS offers many different benefits in addition to the
current IP network. It allows for network traffic engineering to ensure
quality of service (QoS), reliability, security and data transfer efficiency.
This list is only a mere fraction of the list of benefits MPLS brings to the IP
based networking domain. In depth research is needed for one to
understand the depth and breadth of the benefits MPLS brings to our
current networking architecture.

3. What is wrong with what we have now?
As the internet becomes the standard medium to carry information to and
from their destination we will see traditional protocols and hardware be
pushed to their operating thresholds. How do we solve the problem of
increased demands for quality network bandwidth? How do we guarantee
our packets will get from our sources to our intended destinations without
loss delay and most importantly of all how can we know that are packets
are traveling thru authorized secure networks?
Traditional networking infrastructure relay packets of information via
routers that determine the next best path each packet was to take. Based
on different routing algorithms each packet was sent down the shortest
path or quickest path whichever is deemed to be the priority. Each time a
packet arrived at a router their fate would be determined by a routing table
governed by complex algorithms. The most basic constructs of IP routing
do not include considerations to the quality of network that the packet will
travel nor does it take into account what is the most secure path a packet
can take. It is only concerned with how it can get a packet to its
destination while minimizing the distance (hops). MPLS or Multi Protocol
Label switch is the answer to our concerns above. Since traditional IP
networks have no means of labeling, categorizing or monitoring the
packets that traverse them it is nearly impossible to track and direct
specific packets to ensure that priority packets get to their destination via
the right channels. MPLS technology works to solve these IP
shortcomings.
What is MPLS
MPLS is an “overlay” protocol, meaning that MPLS uses the existing
structure of traditional IP switching enhanced with label or tags to aid in
this new way of relaying packets. MPLS takes advantage of all the
benefits of traditional IP switching and adds to it the benefits of network
quality assurance and security management.
Technically MPLS is nothing more than a label header encapsulated into
the IP packet header. This label is used to categorize the packet as it
travels across the physical network thus enabling the ability for it to be
monitored tracked. MPLS hardware transforms the standard IP packets
into MPLS packets adding and subtracting labeling information as they
enter and leave the network. This ensures compatibility to current
consumer computer equipment and eliminates the need for end users to
make hardware upgrades to take advantage of the benefits of MPLS.

4. How it works: MPLS
MPLS-equipped networks use MPLS-aware devices known as label edge
routers (LERs), positioned at the network’s edges. These devices are
designed to inspect IP packets entering the network and add MPLS
headers, as well as removing the headers from packets leaving the MPLS
network. Inside the boundaries of the MPLS network, devices known as
label switch routers (LSRs) look for an MPLS label on each packet as they
passes through them. By looking up and following the instructions
contained in those labels and routing them based on a list of instructions
we obtain the ability to control, monitor and direct packets to and from
network paths of our choice.
Diagram A - http://www.nwfusion.com/news/tech/0524tech.html
Benefits Derivations
• Security
• Quality of Service (QoS)
• Routing Efficiency
• Backward compatibility and Cost efficiency
• Traffic Engineering

5. Applications: Where can MPLS thrive?
MPLS technology main thrives in large network implementations where
mass amounts of data needs to be transmitted through different physical
networks quickly, efficiently and securely. In many cases finding the
optimal path of information is not an easy task. Network administrators
need the flexibility to dictate where on the network specific packets of
information must flow based on technical or business criteria. MPLS
allows network administrators the ability to direct critical traffic thru only
secure networks and non critical data thru general network backbone
connections.
The greatest and simplest example of current technology that can use the
strengths of MPLS technology is VPN (Virtual private networking). VPN is
the establishment of a secure connection to a host severs thru insecure
networks (such as the internet) often known as tunneling.
Diagram B - http://www.helpdesk.umd.edu/topics/applications/vpn/3836

6. Diagram C - http://www.helpdesk.umd.edu/topics/applications/vpn/3836
As described in the diagrams above users create a “tunneled” secure
connection to specific host servers passing thru unknown physical
networks of the internet domain. Packets may very well travel thru
networks belonging to malicious hackers. Even though this information is
often encrypted hackers can and will find a way to intercept and decrypted
messages that pass thru their networks.
MPLS can mitigate this security threat completely. As network
administrator you may be required to establish a VPN connection between
two locations. The data sent maybe extremely sensitive. With MPLS and
VPN technology you will be able to establish a connection and ensure that
this information only travels via certain trusted networks. Doing so can
ensure data is transferred safely, securely and efficiently. In the diagrams
below you will see the concepts of VPN without MPLS and VPN with
MPLS illustrated. The main difference is VPN connection established via
MPSL will travel via Virtually Leased Lines (VLL). These lines are provided
by large network service providers which ensure the lines are secure and
always are of highest quality.

7. Diagram D - http://www.netcraftsmen.net/welcher/papers/mplsvpn.html
Diagram E - http://www.foundrynet.com/solutions/appNotes/PDFs/DM_VLL.pdf

8. Conclusion
Since the exponential like growth of the internet we have noticed
correlating phenomena that hardware limits are being pushed to
dangerously instable levels. By devising new and more cleaver ways to
route information to and from different locations we can accommodate the
increasing demands while postponing the changing of standards and
expenditure. We can use what we have now in smarter more efficient
ways postpone the need to expand or upgrade our current network
systems. MPLS is the solution to our ever expanding internet usage. By
use of cleaver routing techniques not only can we achieve more efficient
usage of our physical networks but we can also have the additional
benefits of security and flexibility.
Bibliography
Author Unknown
Introduction to MPLS .. Explaining Multi-protocol Label Switching
Retrieved Feb 28th, 2004 from
http://findvpn.com/articles/mpls.php