HLP

Abstract

It is well-known that BGP, the current inter-domain routing protocol, has many deficiencies. This paper describes a hybrid link-state and path-vector protocol called HLP as an alternative to BGP that has vastly better scalability, isolation and convergence properties. Using current BGP routing information, we show that HLP, in comparison to BGP, can reduce the churn-rate of route updates by a factor 400 as well as isolate the effect of routing events to a region 100 times smaller than that of BGP. For a majority of Internet routes, HLP guarantees worst-case linear-time convergence. We also describe a prototype implementation of HLP on top of the XORP router platform. HLP is not intended to be a finished and final proposal for a replacement for BGP, but is instead offered as a starting point for debates about the nature of the next-generation inter-domain routing protocol.

Routing centralization across domains via SDN: A model and emulation framework for BGP evolution

“…Hybrid routing. Finally, we have seen proposals of new inter-domain routing protocols with better properties than BGP, such as HLP [39], involving link-state routing within the customer cones of tier-1 ISPs and path-vector routing between tier-1s. Alim and Griffin [40] decompose the algebraic specification of a path problem into sub-problems where different protocols are applied.…”

“…Alim and Griffin [40] decompose the algebraic specification of a path problem into sub-problems where different protocols are applied. The authors attempt to clarify the trade-offs between fast convergence of link-state and low space requirements of path-vector; however, modeling mixed BGP-like protocols such as HLP [39] is still an open problem due to the inability to adequately model BGP with semirings. In contrast, we emulate a hybrid path-vector and link-state multi-AS environment using production BGP and SDN code, and we measure their interplay regarding convergence as a use case.…”

“…For example, we can have lower convergence times and also decreased churn through centrally controlling the dynamics of intra-cluster routing, as we will show in Section 6, or new services, discussed in Section 7. Additionally, hierarchical routing, which benefits routing scalability [39], is enabled at the inter-AS level thus allowing hierarchical routing schemes to flourish along the NOS control chain.…”