Optimizing Traffic Flow with Akamai#

Kams Yeung - Akamai

• Why: Understanding why conventional BGP traffic engineering does not move a major CDN is operationally important for capacity planning and interconnect strategy at any eyeball network.
• What: Akamai maps users via DNS (unicast, per-requester answers based on latency, throughput, loss, server load, cache policy) — not anycast — so AS-path prepending, MED, and more-specific advertisements all do nothing. Clusters are islands (no inter-cluster backbone) with preference on-net cache > PNI > IX > transit. Operator guidance: run your own recursive resolvers with anycast IPs and per-location external IPs (mapping follows the resolver's IP), ACL them, never rewrite Akamai hostnames' TTLs, or else use Google/OpenDNS with ECS; announce complete and consistent prefixes (both DNS and end-user ranges) or risk whole-ASN blocking; carry everything you announce — no holes or filtered /24s, since Akamai edge routers don't hold full tables; don't filter or rate-limit ICMP (used for performance monitoring); avoid CGNAT (or use 100.64.0.0/10 and place caches outside CGNAT); and enable IPv6 — Australia sits at 30.1% adoption, ranked #69, with Telstra at 60.3% and TPG at 24.7%.
• How: Explanation of the mapping system followed by a concrete do/don't list for ISPs.
• Where applicable: Networks delivering Akamai-served content (i.e., most eyeball ISPs). A vendor session, but framed as operational guidance rather than a product pitch.