CANI SMC - Submarine cable connecting Andaman and Nicobar islands

Earlier in March I visited Andaman & Nicobar Islands. The trip was purely personal as my wife happened to have been born there. These are Indian islands in the Bay of Bengal located in the South East of West Bengal and geographically quite near Myanmar and Thailand. The nearest large Indian cities on the mainland are Kolkata and Chennai.

In the initial part of the trip, we stayed in Swaraj Dweep (old name Havelock islands) and later in Port Blair. The place is isolated and has amazing natural beauty. It has one of the most beautiful beaches in the world (Radhanagar Beach). Tourism has grown nicely in Andaman & Nicobar islands in recent years and besides many other factors, one of that is a submarine cable!

No, I am referring to internet infrastructure enthusiasts suddenly visiting the islands but the fact that connectivity is getting pretty good over there. All this dramatically improved by the end of 2020.

CANI SMC - Chennai Andaman Nicobar Islands Submarine Cable

Until Dec 2020 Andaman and Nicobar Islands had no optical fibre backhaul connectivity with mainland India. They heavily relied on super slow Geo-stationary satellites for the island’s backhaul. No 4G, no 3G and barely working 2G coverage for most of the island and of course not much on the fixed line broadband either. All these technologies (2G, 3G, 4G, fixed FTTH) etc are fine but they need backhaul connectivity to the content sources, large datacenters, internet exchange points etc. Capacity was barely 1Gbps for the entire island and 20Mbps for Swaraj Dweep as per this old news report from 2016 in The Daily Telegrams.

Somewhere around 2018 Govt. of India decided to invest $175 million to connect Andaman and Nicobar Islands with Chennai with a submarine fibre optic cable. I think geographically West Bengal is slightly closer but it made sense technically to connect Port Blair (state capital) to Chennai instead of somewhere in West Bengal. There are a bunch of Submarine cables landing in Chennai, there is infra already present for the landing station and it’s just overall easier to provision large capacity from Chennai. The project is called CANI SMC - Chennai Andaman Nicobar Islands Submarine Cable. Govt. assigned BSNL for this cable and BSNL contracted it to NEC India for this cable. Ultimately one of the islands (other than Port Blair) has to be connected to some other key location in mainland India (possibly West Bengal) to complete the ring and have basic protection again fibre cuts.

Design & Capacity

This system is designed with keeping a linear flow for the most part. The main long-distance cable connects Chennai to Port Blair with a 2 x 200G (400Gbps) capacity and from Port Blair and then 200G from Port Blair onwards to 7 islands. One branch connects Port Blair to Swaraj Dweep, Long Island and Rangat in the North and the other branch connects Port Blair to Little Andaman, Car Nicobar, Kamorta and Great Nicobar Islands.

Source of image & more info here.

Everyone knows

I have been to a few submarine landing stations around the world. One unique factor about CANI-SMC is that literally everyone knows about it. On my first day in Swaraj Dweep, I asked the auto driver on which mobile network he uses. He mentioned BSNL & immediately followed that connectivity has dramatically improved since the landing of the submarine cable. I was pleasantly surprised to hear the term “submarine cable” from the auto driver. He even told me he can show the landing station from outside. I couldn’t have said no and here’s how it looks!

Typically submarine cable lands on a less-crowded area of a beach and then it is spliced into in-land cable on a “landing pit”. This is because the submarine cable is pretty hard to work with when it’s outside of the sea. It has massive steel wire armour around it to protect it. Next, the in-land cable connects to a nearby landing station which houses DWDM as well as power equipment. These cables do carry electric power as well to power repeaters every 80-100Km or so. Typically it’s a very high voltage DC with one landing station giving a few thousand -ve potential and the other end giving a few thousand +ve potential.

From the landing pit, it seems to be following multiple paths which were marked around the pillars - Path A (in red) and Path B (in yellow). I saw the landing pit near the beach but couldn’t take a picture as my son wanted us to just jump in the water. 😄

Next, in Port Blair again I asked the taxi driver about connectivity and as expected - he immediately pointed to the submarine cable & even told me the exact landing location. Port Blair seems to have more beaches and it wouldn’t be easy to just find the landing pits unless one has a clue. The hard way can always be to follow the road the marks. I did see CANI SMC roadside pillars next to my hotel as well as on major roads around Port Blair.

This is the submarine cable landing pit in Port Blair.

Network operators who use this cable


This cable is a perfect example of what neutral infrastructure is. BSNL maintains it and leases out capacity to Airtel, Jio, VI etc. All the services from wireless to fixed wireline backhaul over this cable. Internal connectivity within Swaraj Dweep is being developed now. I saw a bit of ongoing work by Jio in putting in land cables, Airtel and BSNL already had a presence there. In the state capital, Port Blair connectivity felt as good as in any other place in India. From mobile coverage to speeds, latency etc it felt very much like what one can get in Haryana, Delhi, Mumbai etc. The hotel where we stayed in Swaraj island had the BSNL FTTH provisioned over BBNL fibre. There are considerable FTTH deployment efforts ongoing for now. Govt can/should do large-scale backhaul infrastructure projects but should stay away from providing services on the last mile for retail users. It just does not scale up. If BSNL is today maintained as a backhaul it can do a lot with its 600,000km of fibre spread across the country. But it must exit retail services where they will keep bleeding money.

Here’s a view of latency to the Airtel Ookla speed test server in Port Blair from Haryana:

Since the other end of the cable connects to Chennai, latency to Chennai matters. Beyond that large part of local caches exists within Chennai for Airtel/Jio/BSNL etc. The latency between Port Blair and Chennai is 17.3ms.

PING ( 56(84) bytes of data.
64 bytes from icmp_seq=1 ttl=58 time=17.3 ms
64 bytes from icmp_seq=2 ttl=58 time=17.3 ms
64 bytes from icmp_seq=3 ttl=58 time=17.3 ms
64 bytes from icmp_seq=4 ttl=58 time=17.3 ms

--- ping statistics ---
4 packets transmitted, 4 received, 0% packet loss, time 3004ms
rtt min/avg/max/mdev = 17.354/17.365/17.373/0.131 ms

Next time you are in Andaman and sending pictures out, do remember the effort it would have taken to put in a 2300km long submarine cable to make it work.