[122664] in North American Network Operators' Group
MLFR Differential Delay Problems
daemon@ATHENA.MIT.EDU (R. Benjamin Kessler)
Thu Feb 18 22:55:34 2010
Date: Thu, 18 Feb 2010 22:54:57 -0500
From: "R. Benjamin Kessler" <rbk@mnsginc.com>
To: <nanog@nanog.org>
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
Hello NANOGers -=20
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I'm working on a project to migrate a customer from one "Tier 1"
provider to another at 50+ locations (all domestic US sites). Most of
these connections are 4xT1 multi-link bundles.
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The old router configuration was MLPPP which was rock-solid for 3 years
(save for the typical "last-mile" circuit issues, fiber-cuts, etc.).
The new carrier uses FRF.16 multi-link Frame Relay vs. MLPPP.
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We've completed the migration on 10+ sites and all of them are now
reporting errors like the following:
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Feb 17 21:01:39 /kernel: MFR bundle ls-0/0/0:0 link t1-1/0/0
differential 91.7 ms over yellow differential delay 75 ms
Feb 17 21:01:50 /kernel: MFR bundle ls-0/0/0:0 link t1-1/0/0
differential 115.9 ms over yellow differential delay 75 ms
Feb 17 21:01:50 /kernel: MFR bundle ls-0/0/0:0 link t1-1/0/1
differential 79.0 ms over yellow differential delay 75 ms
Feb 17 21:01:50 /kernel: MFR bundle ls-0/0/0:0 link t1-2/0/1
differential 79.1 ms over yellow differential delay 75 ms
Feb 17 21:01:50 /kernel: MFR bundle ls-0/0/0:0 link t1-1/0/1
differential 97.4 ms over yellow differential delay 75 ms
Feb 17 21:01:50 /kernel: MFR bundle ls-0/0/0:0 link t1-2/0/0
differential 97.5 ms over yellow differential delay 75 ms
Feb 17 21:01:50 /kernel: MFR bundle ls-0/0/0:0 link t1-2/0/1
differential 97.5 ms over yellow differential delay 75 ms
Feb 17 21:01:52 /kernel: MFR bundle ls-0/0/0:0 link t1-1/0/1
differential 97.4 ms over yellow differential delay 75 ms
Feb 17 21:01:52 /kernel: MFR bundle ls-0/0/0:0 link t1-2/0/0
differential 97.5 ms over yellow differential delay 75 ms
Feb 17 21:01:52 /kernel: MFR bundle ls-0/0/0:0 link t1-2/0/1
differential 97.5 ms over yellow differential delay 75 ms
Feb 17 21:01:53 /kernel: MFR bundle ls-0/0/0:0 link t1-1/0/1
differential 90.0 ms over yellow differential delay 75 ms
Feb 17 21:01:53 /kernel: MFR bundle ls-0/0/0:0 link t1-2/0/1
differential 100.0 ms over yellow differential delay 75 ms
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The customer routers are all Juniper J6350; I believe the Carrier's
routers are all Cisco GSRs.
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Advanced JTAC says that our configurations are solid and that there are
no known bugs that would exhibit behavior like this. The carrier is
insisting on performing physical-level tests of the circuits (even
though they're running error free) before they'll engage higher-level
engineers so I'm currently in a holding pattern awaiting those results.
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My Google-foo is failing me and I'm not able to find any documents that
help explain what may be causing this and how to troubleshoot and find
an eventual solution.
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I would really appreciate any tips or suggestions from anyone on the
list that may have seen issues like this in the past.
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Thanks,
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Ben
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