On 28-7-2015 20:43, John MacAuley wrote:

We encountered an interesting issue on the AutomatedGOLE over the last week. [...]

iCAIR and Netherlight have set up a peering over a link that traverses WIX. The bidirectional port on the iCAIR side is defined with a VLAN range of 1779-1798 while the Netherlight side is defined with a range of 4020-4039. WIX performs mapping between the ranges without any involvement from NSI (WIX is not yet under NSI control). [...]

There are two solutions to this problem (assuming the VLANs must stay mismatched):

1. Get WIX under NSI control and programatically control the switching. In this case the topology changes from iCAIR - Netherlight to iCAIR - WIX - Netherlight and we get a new NML description that allows pathfinders to compute the WIX translation themselves.

2. If we cannot get control of the mid switching point then the only alternative would be to modify the two ends (iCAIR and Netherlight) to do manual mappings for each VLAN. This means more NML entries, but it would let the pathfinder figure out which VLANs are interconnected. [...]

Each VLAN mapping would be modelled individually, with in and out unidirectional NML elements, as well as individual bidirectional elements. A lot more work but is a way to get around the problem we are seeing. [..]

Hi John, Very astute observation. You are completely correct, and this is as-designed. Solution 2 works. It is not pretty, but that's just because the reality aint pretty. You have to revert to low level fidgeting. I'm at least pleased to hear that it works in the end. Of course, we can all agree that if WIX implements NSI, that would be a lot prettier and easier! Freek