Re: Concerning MPLS paths
How about when William says LSPs are not static. Does he mean not static as in path may change, or that the bandwidth reserved for the LSP may change? And thanks Marshall for the reply. On Mon, Apr 27, 2009 at 5:41 PM, William McCall william.mcc...@gmail.comwrote: Well, yes (if you don't count the additional traffic of signalling/routing protocols, label imposition, etc) but consider the fact that topologies change and routing will tend to change the total traffic handled through a node. LSPs are not static unless you use TE tunnels. Remember that labels are Forwarding Equivalency Classes and that translates into subnets (whether they're subnets in a L3 vpn or part of the P network) and the routing is still handled through an IGP or BGP. HTH --WJM IV On Mon, Apr 27, 2009 at 7:10 AM, Saqib Ilyas msa...@gmail.com wrote: Hello everyone In the context of a single service provider network running MPLS, if a number of bandwidth constrained LSPs are passing through a particular node and the sum of the bandwidth constraints for the LSPs is X Mb/s, then is X the upper bound on the traffic through that node, or is it sometimes exceeded as well? Thanks and best regards -- Muhammad Saqib Ilyas PhD Student, Computer Science and Engineering Lahore University of Management Sciences -- Muhammad Saqib Ilyas PhD Student, Computer Science and Engineering Lahore University of Management Sciences
Re: Concerning MPLS paths
On Apr 28, 2009, at 4:51 AM, Saqib Ilyas wrote: Anyone? On Mon, Apr 27, 2009 at 6:15 PM, Saqib Ilyas msa...@gmail.com wrote: Furthermore, I was also wondering, if the bandwidth constraints are upper bounds, what does the traffic distribution typically look like at an LSR? It clearly depends on what that traffic is. The MPLS services I am most familiar with carry video traffic, with traffic patterns that look very different from the typical web site (generally the traffic is either on or off, there is very little burstiness, there can be long periods of basically full usage of the available bandwidth and, if you commit to X Mbps, you had better actually have it, not X - epsilon). I would guess that this is one end of the spectrum, that bursty web traffic is the other, and that most other uses (such as VOIP) fall somewhere in between. Regards Marshall We're interested in traffic within a single service provider, non- Internet traffic. Perhaps most service providers set aside some (dynamic?) pool for Internet traffic, while making commitments to customer's inter-site traffic. Thanks and best regards On Mon, Apr 27, 2009 at 5:50 PM, Saqib Ilyas msa...@gmail.com wrote: William Thanks for the reply. You say that LSPs are not static unless you use TE tunnels. Are you referring to the staticness in terms of the path or in the amount of bandwidth reserved on each link along a fixed path determined at the time of signalling? Isn't a bandwidth constrained LSP always a TE tunnel? Thanks and best regards On Mon, Apr 27, 2009 at 5:41 PM, William McCall william.mcc...@gmail.com wrote: Well, yes (if you don't count the additional traffic of signalling/routing protocols, label imposition, etc) but consider the fact that topologies change and routing will tend to change the total traffic handled through a node. LSPs are not static unless you use TE tunnels. Remember that labels are Forwarding Equivalency Classes and that translates into subnets (whether they're subnets in a L3 vpn or part of the P network) and the routing is still handled through an IGP or BGP. HTH --WJM IV On Mon, Apr 27, 2009 at 7:10 AM, Saqib Ilyas msa...@gmail.com wrote: Hello everyone In the context of a single service provider network running MPLS, if a number of bandwidth constrained LSPs are passing through a particular node and the sum of the bandwidth constraints for the LSPs is X Mb/s, then is X the upper bound on the traffic through that node, or is it sometimes exceeded as well? Thanks and best regards -- Muhammad Saqib Ilyas PhD Student, Computer Science and Engineering Lahore University of Management Sciences -- Muhammad Saqib Ilyas PhD Student, Computer Science and Engineering Lahore University of Management Sciences -- Muhammad Saqib Ilyas PhD Student, Computer Science and Engineering Lahore University of Management Sciences Regards Marshall Eubanks CEO / AmericaFree.TV
Re: Concerning MPLS paths
Hi, 2009/4/28 Saqib Ilyas msa...@gmail.com: Hello everyone In the context of a single service provider network running MPLS, if a number of bandwidth constrained LSPs are passing through a particular node and the sum of the bandwidth constraints for the LSPs is X Mb/s, then is X the upper bound on the traffic through that node, or is it sometimes exceeded as well? From my experience with RSVP-TE and LSP tunnels the bandwidth you pin down for a tunnel is only reserved, not guaranteed. There is nothing stopping you from creating a 10Mb/s LSP and sending 20Mb/s down through it. By default only the ingress LSR can do the policing/shaping. If you don't to that at the head than the rest of the network will just happily pass the traffic defaulting to its normal queue handling. So to answer to your question is - yes you might see more traffic then you've reserved. kind regards Pshem
Re: Concerning MPLS paths
Well, yes (if you don't count the additional traffic of signalling/routing protocols, label imposition, etc) but consider the fact that topologies change and routing will tend to change the total traffic handled through a node. LSPs are not static unless you use TE tunnels. Remember that labels are Forwarding Equivalency Classes and that translates into subnets (whether they're subnets in a L3 vpn or part of the P network) and the routing is still handled through an IGP or BGP. HTH --WJM IV On Mon, Apr 27, 2009 at 7:10 AM, Saqib Ilyas msa...@gmail.com wrote: Hello everyone In the context of a single service provider network running MPLS, if a number of bandwidth constrained LSPs are passing through a particular node and the sum of the bandwidth constraints for the LSPs is X Mb/s, then is X the upper bound on the traffic through that node, or is it sometimes exceeded as well? Thanks and best regards
Re: Concerning MPLS paths
William Thanks for the reply. You say that LSPs are not static unless you use TE tunnels. Are you referring to the staticness in terms of the path or in the amount of bandwidth reserved on each link along a fixed path determined at the time of signalling? Isn't a bandwidth constrained LSP always a TE tunnel? Thanks and best regards On Mon, Apr 27, 2009 at 5:41 PM, William McCall william.mcc...@gmail.comwrote: Well, yes (if you don't count the additional traffic of signalling/routing protocols, label imposition, etc) but consider the fact that topologies change and routing will tend to change the total traffic handled through a node. LSPs are not static unless you use TE tunnels. Remember that labels are Forwarding Equivalency Classes and that translates into subnets (whether they're subnets in a L3 vpn or part of the P network) and the routing is still handled through an IGP or BGP. HTH --WJM IV On Mon, Apr 27, 2009 at 7:10 AM, Saqib Ilyas msa...@gmail.com wrote: Hello everyone In the context of a single service provider network running MPLS, if a number of bandwidth constrained LSPs are passing through a particular node and the sum of the bandwidth constraints for the LSPs is X Mb/s, then is X the upper bound on the traffic through that node, or is it sometimes exceeded as well? Thanks and best regards -- Muhammad Saqib Ilyas PhD Student, Computer Science and Engineering Lahore University of Management Sciences
Re: Concerning MPLS paths
Furthermore, I was also wondering, if the bandwidth constraints are upper bounds, what does the traffic distribution typically look like at an LSR? We're interested in traffic within a single service provider, non-Internet traffic. Perhaps most service providers set aside some (dynamic?) pool for Internet traffic, while making commitments to customer's inter-site traffic. Thanks and best regards On Mon, Apr 27, 2009 at 5:50 PM, Saqib Ilyas msa...@gmail.com wrote: William Thanks for the reply. You say that LSPs are not static unless you use TE tunnels. Are you referring to the staticness in terms of the path or in the amount of bandwidth reserved on each link along a fixed path determined at the time of signalling? Isn't a bandwidth constrained LSP always a TE tunnel? Thanks and best regards On Mon, Apr 27, 2009 at 5:41 PM, William McCall william.mcc...@gmail.comwrote: Well, yes (if you don't count the additional traffic of signalling/routing protocols, label imposition, etc) but consider the fact that topologies change and routing will tend to change the total traffic handled through a node. LSPs are not static unless you use TE tunnels. Remember that labels are Forwarding Equivalency Classes and that translates into subnets (whether they're subnets in a L3 vpn or part of the P network) and the routing is still handled through an IGP or BGP. HTH --WJM IV On Mon, Apr 27, 2009 at 7:10 AM, Saqib Ilyas msa...@gmail.com wrote: Hello everyone In the context of a single service provider network running MPLS, if a number of bandwidth constrained LSPs are passing through a particular node and the sum of the bandwidth constraints for the LSPs is X Mb/s, then is X the upper bound on the traffic through that node, or is it sometimes exceeded as well? Thanks and best regards -- Muhammad Saqib Ilyas PhD Student, Computer Science and Engineering Lahore University of Management Sciences -- Muhammad Saqib Ilyas PhD Student, Computer Science and Engineering Lahore University of Management Sciences
