The MPLS-OPS Archive[Date Prev][Date Next][Thread Prev][Thread Next] [Date Index][Thread Index][Author Index][Subject Index] Fwd: Conflict in LDP and MPLS
As I understand it, LDP only provides the labels for the next hop for a particular flow, and that happens on every router in the MPLS cloud. A given router accumulates a group of labels, and all of these labels are sufficient to allow the traffic in a particular flow to get to the destination. Then comes a decision for the router: Which of the labels to pick, and what to base the choice on? One way the routers decide is to pick the shortest path, and that is done automagically as the default. Another way of picking is to tell the router which path it should use (explicit tunnel), and that process has some variants. Another way is to declare tunnel endpoints and allow the routers to deal with the physical route within the tunnel (dynamic tunnels). Another way might be bandwidth availability, or other deciding factors The main point of label switching is that you can label traffic, and therefore decide routing, based on things other than destination. In this case SPF isn't the only deciding factor. I hope that helps a bit Roger Williams >X-BrightmailFiltered: true >X-BrightmailFiltered: true >X-Ironport-AV: i="3.85,149,1094454000"; > d="scan'208"; a="5252056:sNHT29996338" >Resent-Date: Mon, 18 Oct 2004 08:35:38 -0400 >X-Authentication-Warning: host.secure4-hosting.net: mplsrc12 set sender to >mpls-ops-request@mplsrc.com using -f >Date: Mon, 18 Oct 2004 05:22:40 -0700 (PDT) >From: vishwanathan mv <cheerfulmvp@yahoo.com> >To: mpls-ops@mplsrc.com >Subject: [MPLS-OPS]: Conflict in LDP and MPLS >Resent-From: mpls-ops@mplsrc.com >X-Mailing-List: <mpls-ops@mplsrc.com> archive/latest/7831 >X-Loop: mpls-ops@mplsrc.com >Resent-Sender: mpls-ops-request@mplsrc.com >X-PMX-Version: 4.7.0.111621 >X-from-outside-Cisco: 128.107.234.206 > >The purpose of using LDP is to automate the label distribution. But the >basic route that the packets take initially is the default ip routes. Is >this what we wanted? Haven't we lost out on our power to use MPLS (design >our own routes) - the reason for which it was designed? I know that using >CR-LDP one can get over this. > >Thanks in advance. > >__________________________________________________ >Do You Yahoo!? >Tired of spam? Yahoo! Mail has the best spam protection around >http://mail.yahoo.com Roger Clark Williams Network Consulting Engineer Global OSS/NMS Practice IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII Cisco Systems, Inc. phone: 978.936.0270 cell: 802.355.9933 email: rogwilli@cisco.com Ignorance more frequently begets confidence than does knowledge. -Charles Darwin, naturalist and author (1809-1882) ------- The MPLS-OPS Mailing List Subscribe/Unsubscribe: http://www.mplsrc.com/mplsops.shtml Archive: http://www.mplsrc.com/mpls-ops_archive.shtml |
|