13 Feb

Indian IPv6 deployment

I had calls with a couple of friends over this week and somehow discussion IPv6 deployment came up. “How much has been IPv6 deployment in India now in 2020” is a very interesting question. It’s often added with – “how much of my traffic will flow over IPv6 once it is enabled“?

Game of numbers

There is a drastic difference in IPv6 deployment depending on which statistic we are looking at here in India. There can be a bunch of factors based on which we can try to judge IPv6 deployment:

  1. How many operators are offering IPv6 to end users?
  2. How many end-users are on IPv6?
  3. How’s the content available on IPv6 in terms of a number of IPv6 enabled websites?
  4. How’s the content available on IPv6 in terms of traffic volume over IPv6?

First two and last two points are related and point towards from vertically opposite ends. (Call it good or bad) the fact of high centralisation. There has been an ongoing centralisation of mobile operators and in-country like ours they connect a very large number of end-users. The number of fixed-line networks has increased considerably but at the same time in proportion to a number of mobile users they user base growth has been much lower.

On the content side like everywhere else in the world, there’s a lot more centralisation of content. Many of my Indian ISP friends tell me that Google + Akamai + Microsoft + Netflix + Facebook + Cloudflare is way over 75% of their traffic. Think about it, that’s just 6 AS number out of 68000+ odd networks in the world as per BGP routing table. Thus by traffic profile, we are looking at 0.0014% networks serving 75% of content traffic. The reason for such centralisation is actually beyond network and more around the success of products of these organisations followed by factors like the winner (or top 3) gets it all in most of these domains.

For eyeball traffic APNIC IPv6 stats for India (source here) as well as Hurricane Electric’s IPv6 progress report (source here) give us some numbers:

  1. Very few fixed-line operators are offering IPv6 but on the mobile side – a large number of mobile networks are offering IPv6. Jio was on IPv6 since launch and as traffic increased, Airtel as well as Vodafone + IDEA also significantly increased their deployment. On fixed line, it’s just Jio + ACT broadband with any sizable IPv6 footprint. BSNL + Airtel have virtually no deployment. There might be some other network in the list but it’s off the radar.
  2. There are a lot more end users on IPv6 than despite the small number of networks offering it because of the large mobile user base. On Jio 80%+ user base, on Airtel, it’s 45%, on Vodafone & IDEA (merged company but still separate ASNs) it’s close to 50%. That’s the number of users who are connecting over IPv6 when given option of IPv4 and IPv6 as tested by APNIC. That number is huge!
  3. Around 98.5% of TLDs (top-level domain names like .com, .net etc) are IPv6 enabled. For .com & .net domains, only 7% of the domains have an AAAA record (compared to ones having an A record). Most of the numbers are much lower if we look at the content side of IPv6 (ignoring the traffic volume).
  4. If we look at the content players with IPv6 and include the traffic volume numbers then it’s way higher. It is estimated that globally somewhere between 20-30 top ASNs carry 90%+ traffic and almost all of those top 20 are IPv6 enabled.

What do all these numbers actually mean?

  1. If you are an eyeball network in India and you deploy IPv6, you can expect way over 70-80% traffic (by volume) on IPv6.
  2. If you are a content network/datacenter in India and application is targetting to home fixed-line / enterprise network, expect a rather low amount of IPv6 traffic but would be rapidly increasing as more fixed-line networks deploy.
  3. If you are a content network/datacenter in India and content hosted at your end attracts mobile traffic, you can expect way over 50%-60% of that mobile traffic over IPv6.

Some additional reasons to consider deploying IPv6

  1. In India, ISPs need to maintain carrier-grade NAT logs of the translations. If one is doing dual-stack, a large part of traffic will flow over IPv6 saving on those logging requirements.
  2. For ISPs, it will save you from significant strain on CGNAT device.
  3. For content network/webmaster/datacenter – IPv6 will help in delivering your traffic outside of (often) congested CGNAT paths.

Happy IPv6ing! 🙂

04 Jan

VoWifi experience on Jio

Since last week of Nov 2019, I am having serious issues with Airtel at my home. Somehow 4G signal SNR is very poor and most of the calls just fail on that. Airtel support just mentioned that they are putting a new site in my area in Jan 2020 but fail to explain why suddenly it went so bad. I can imagine that support team staff does not have visibility to network in real-time and likely it would be an issue with the 4G antenna on one or more towers. 2G signal was good but latency was extremely high to connect call plus calls still failed regardless (maybe due to high strain on 2G).

So by the end of December, I just gave up and gave the request for porting to Jio. Yesterday my number started on Jio and around 24 hours later I got access to VoWifi which is quite nice. Both Airtel & Jio are rolling our VoWifi but for Airtel, many users have reported it for being locked on Airtel fixed line only.

What is VoWifi?

Well, it’s just native offloading of voice calls over the fixed-line network and is extremely useful for both network operators as well as end-users. Native IP equipment is cheap and it’s way easy to extend cell coverage at home via Wifi instead of proprietary inbuilding solutions. Plus landline was good for quality but form factor and usability was pain. Now VoWifi kind of merges the fixed-line and cell phones and we get best of both worlds.

I think many people confused BSNL Wings with VoWifi. VoWifi is seamless offloading of calls natively while BSNL Wings offered a separate number, an app to run and a separate billing account to maintain with the operator. BSNL Wings was a bad product idea and really awful execution.

Coming to Jio VoWifi, some misc observations:

  1. It’s working for me on the non-Jio fixed-line connection in Haryana circle. I have IAXN (GEPON FTTH) and Siti broadband (DOCSIS 3.0) at home running in active/backup configuration for high availability.
  2. The device has an IPsec tunnel with 49.44.59.XXX. I see isakmp-nat-keep-alive packets every 20 seconds when I do tcpdump on the router.
  3. On my cell phone (which is an Apple iOS device) I see a tunnel is opened on IPSEC1 port. IPSEC2 & IPSEC3 are there for VoLTE.
    IPSEC1 has a link-local IPv6 and an IPv6 from 2405:205:3000::/36 range. The IPv6 on all three IPSEC tunnels is the same as of pdp_ip1 (Cellular data port). I guess that’s probably how they are handing the handovers between VoWifi and VoLTE.
  4. The IPv6 on pdp_ip0 for cellular data is from a different range which again is being announced in the global table as 2409:4051::/36. I wonder why Jio is using publically routable pool for VoLTE and VoWifi. In case of Airtel it a non-routed address space and routes are not announced in the global routing table.
  5. In my test VoWifi to VoLTE was reasonably OK. I tested by shutting off wifi on the cell phone as well as unplugging the cable from wifi AP to test. In both cases call went silent for 1-2 seconds and resumed over VoLTE. It did not come back on VoWifi once Wifi was back live.
  6. Latency from both connections to other endpoint (the router before the IPSEC endpoint) is around 60ms. Either the endpoint is somewhere far off or (more likely) it’s a case of not-so-good routing between Airtel (upstream of my ISP) and Jio.
  7. There’s a quite noticeable improvement in connection time. For IVR based numbers it’s close to 2-3 seconds. Which is a great improvement for someone like me who was on 2G non-VoLTE calls for December!

How to check interfaces and routing table on your phone?

Well use HE.NET Network App on Android or Apple iPhone and you will be able to check that!

That’s about it. Back to the world of routing. 🙂