Kolkata IX

An internet exchange is shared switching where networks interconnect directly instead of paying a transit provider to carry traffic between them. Members take a port on the fabric and an address on the peering LANs below, then agree bilaterally (or through a route server) about which routes to exchange. Turning up at one is a deliberate choice about how a network wants to be reached, which is why exchange presence says something a routing table cannot.

Location

Kolkata, India

Region

Asia-Pacific

Airport code

CCU

Status

Active

PCH record updated

2019-05-03

Everything on this page is what Packet Clearing House had recorded when the directory was collected, not a live view of the fabric. Member counts in particular lag reality, and around 45% of the exchanges in this dataset publish no participant list at all.

The shared subnets members take an address on. A network with an interface in one of these blocks is at this exchange by definition, which is what makes exchange presence a recorded fact rather than an inference. Most exchanges run one IPv4 and one IPv6 LAN; extra blocks are usually growth or a migration.

Deprecated and retired blocks are listed rather than dropped. A decommissioned LAN still records how this fabric used to be reached, and filtering it would quietly rewrite the exchange's history.

Every network PCH records with an address on one of the peering LANs above, ordered as the source ranks them: the most-connected participants first. One row per recorded address, so a network running dual-stack appears once for its IPv4 interface and once for its IPv6 one.

Peering policy is what the network declared to PCH, not something anyone verified, and an open policy is an invitation rather than a commitment. Absence of a network here means PCH has no record of it at this exchange, not that it is not present.

• Full record at Packet Clearing House — the upstream this page is built from, with the traffic graphs and the complete participant list.
• The exchange's own site — joining terms, port pricing and the route servers, which no directory carries.

Exchange records come from the directory collected 2026-08-09 by Packet Clearing House (https://www.pch.net/ixp/data), covering 1,327 exchanges and 93,164 recorded member addresses, licensed CC BY-NC-SA 3.0.

This is a snapshot, not a live view. Members join and leave continuously, and the figures above are what PCH had on file on the collection date. PeeringDB is the better-known directory and is deliberately not the source here: its acceptable-use policy forbids the bulk storage this needs. The two answer different questions anyway. PeeringDB reports what an operator declares about itself; this reports what PCH has recorded.