mpls

[carl_townshend]

Can anyone tell me why people use mpls and what the benifits are over normal wan routing ?

[gauravprakash]

Hi,

MPLS has many unique advantages.. to be brief its best of both world : doing switching ( based on labels/tags ) based on inputs from routing.

You can hv a link..

http://www.cisco.com/en/US/products/ps6557/products_ios_technology_home.html

Regards,

G

[JohnHumphrey]

IP JOURNAL Article on MPLS

My organization is currently implementing a Managed MPLS Network with Verizon Business. I am learning a lot very quickly from the frying-pan point-of-view. As you are, I am constantly on the lookout for good MPLS info. Since I work from several different computers, I do not have all my links available with me today.

I do want point out a FREE service from Cisco that I noticed a couple nights ago. Since Cisco's other periodicals are currently being retired, I wanted to try to generate renewed interest in the "IP JOURNAL". It is a quarterly Journal that has been published for Networking Engineers since 1998. In their 4th Year(2001), there was a VERY GOOD 14 page article explaining the emerginging technology of MPLS, and it obviously has really blown up from there. Please read the article and subscribe to the "IP JOURNAL", so we can keep the great information coming. Thanks.

Internet Protocol Journal:

http://www.cisco.com/web/about/ac123/ac147/about_cisco_the_internet_protocol_journal.html

The Internet Protocol Journal - Volume 4, Number 3, Article on MPLS:

http://www.cisco.com/web/about/ac123/ac147/archived_issues/ipj_4-3/mpls.html

You can download all the old back issues in PDF format and read them later at your leisure. I have them all saved on my work computer, and I look forward to reading every one of them. :-)

[JohnHumphrey]

See above for the link to the rest of the following article:

MPLS

By: William Stallings

"Multiprotocol Label Switching (MPLS) is a promising effort to provide the kind of traffic management and connection-oriented Quality of Service (QoS) support found in Asynchronous Transfer Mode (ATM) networks, to speed up the IP packet-forwarding process, and to retain the flexibility of an IP-based networking approach.

Background

The roots of MPLS go back to numerous efforts in the mid-1990s to combine IP and ATM technologies. The first such effort to reach the marketplace was IP switching, developed by Ipsilon. To compete with this offering, numerous other companies announced their own products, notably Cisco Systems (Tag Switching), IBM (aggregate routebased IP switching), and Cascade (IP Navigator). The goal of all these products was to improve the throughput and delay performance of IP, and all took the same basic approach: Use a standard routing protocol such as Open Shortest Path First (OSPF) to define paths between endpoints; assign packets to these paths as they enter the network; and use ATM switches to move packets along the paths. When these products came out, ATM switches were much faster than IP routers, and the intent was to improve performance by pushing as much of the traffic as possible down to the ATM level and using ATM switching hardware." ...

Article on MPLS:

http://www.cisco.com/web/about/ac123/ac147/archived_issues/ipj_4-3/mpls.html

[scottmac]

The short story Carl is, two usual reasons:

You can apply a tag (label) to traffic. The label applys a rule or set of rule to that traffic, most frequently Quality of Service assignments.

Carrier-provided MPLS tends to take on a configuration where there is one Frame-Relay DLCI that carries all traffic. The traffic is "sorted" at the first Provider Edge router (the PE) according to its IP address and the appropriate label is applied.

MPLS can provide end-to-end quality of service.

The second use is for traffic engineering. One of the rules that can be applied to a label is what the next hop will be.

You can have one traffic stream route through the northern US and another traffic stream routed through the southern US, for example (in the same cloud ... like static routing through a specific path, even though it might appear to the endpoints as a "sub-optimal" path).

Traffic engineering can also give the carrier some options for distributing the traffic through their cloud.

FWIW

Scott