Every carrier calls it something different, but it boils down to a VLAN on the carrier's port that takes you PtP to another site. For example:
Dallas datacenter has a NNI with Provider. On that NNI, you've been given VLAN 101 that PtPs to Site. Atlanta datacenter has a NNI with Provider. On that NNI, you've been given VLAN 201 that PtPs to Site. Site has an "Enhanced" UNI where Provider has given you 2 VLANs. VLAN 101 is PtP to Dallas, VLAN 201 is PtP to Atlanta. Some MEF-head will surely correct the terminology here, but having worked with just about every national carrier, they all use the terms in different ways. ...Or, you can buy an E-LAN type service that is any-to-any and then do your own network over top of it. Most problems I've had with E-LANs revolve around spanning-tree (make sure your edge devices aren't sending BPDUs into the E-LAN) or the provider VPLS locking up where certain endpoints can't be seen from other endpoints. Be prepared to recover your network using hairpin routing from a couple of sites while the provider resets everything. Eric ________________________________ From: Mark Blackford via NANOG <[email protected]> Sent: Friday, January 16, 2026 8:33 AM To: North American Network Operators Group <[email protected]> Cc: Mark Blackford <[email protected]> Subject: Exploring EVPL / NNI redundancy options Does anyone have experience implementing redundancy on their EVPL services within the same carrier? For instance, I have many point-to-point scenarios using EVPL providers to connect sites to Dallas. I’m looking to add a new pop in Atlanta this year for expansion and redundancy. It seems possible to have a “Site A” with a current drop off NNI in Dallas added to the new POP on Atlanta within the same carrier network for data center redundancy, but I am not sure how practical that is in terms of cost and implementation. Latency would vary of course, and I am assuming they give you a different VLAN (but maybe not?). I welcome any comments like if this is a good idea or not, what carriers I should consider, and experience with cost. Thanks in advance! Mark Blackford _______________________________________________ NANOG mailing list https://lists.nanog.org/archives/list/[email protected]/message/74Z7PWTPKK3SBFXS4BFAMC7BFV5WY4KV/ _______________________________________________ NANOG mailing list https://lists.nanog.org/archives/list/[email protected]/message/AL6TK6FMWCV6A53IEHI3Y2MAPQP5GPFM/
