Merging Service Provider Networks#

Markus Jungbluth, Bastian Hoss (Xantaro)

• Why: German SP market consolidation makes network merging a recurring challenge. This talk covers the technical approaches (NNI, Inter-Provider options A/B/C, Seamless MPLS) and challenges (IGP merging, low-scale access devices) — relevant to the PM's broader network architecture interests.
• What: A technical walkthrough of IP/MPLS network integration post-acquisition: three approaches (NNIs, Inter-Provider eBGP per RFC 4364 Options A/B/C, Carrier-of-Carrier VPNs), why they're all "quick fixes" that leave networks administratively separate, and how Seamless MPLS (BGP-LU, IGP separation, route summarization) builds the real bridges. Covers low-scale access devices (~500-2k FIB) as the weakest link, and a novel ISIS LSDB simulation technique for pre-merger testing.
• How: BGP-LU distributes transport labels via BGP without requiring LDP/IGP, enabling low-scale devices to participate with a default route + filtered BGP-LU routes. The lab simulation technique exported ISIS LSPs from both networks, manipulated them to simulate a merged LSDB, and transmitted it to a DUT via a customized ISIS implementation — proving the DUT wouldn't fail post-merger.
• Where applicable: Service providers going through M&A. The Seamless MPLS toolbox and low-scale-device separation patterns apply to any large network with heterogeneous device capabilities. Xantaro-specific deployment experience but the techniques are standards-based.