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. 🙂

26 Aug

Facebook FNA Nodes Updates

Earlier this year after APRICOT 2018, I posted a list of visible Facebook FNA (CDN caching) nodes across the world with IPv4, IPv6 and the AS name. I got quite a few mails in following months about people mentioning that they installed nodes but do not see their names in the list (and that was normal since list was static). 

I re-ran my script to see emailslatest status of nodes. During last check I saw 1689  nodes (3rd March). Now on 26th Aug i.e after close to 6 months, the total number of nodes has increased to 2204.

Here is the latest sheet containing the list of nodes with ASN, network name, IPv4 and IPv6 – http://link.anuragbhatia.com/fna30aug

Summary of the data and some findings for India

  1. The number of nodes increased by 27% within the last 6 months. 

  2. On Reliance Jio network number of node increased by just 1 – which is a new node they put in Ludhiana, Punjab. 

  3. In Delhi, a number of FNA nodes went up from 16 to 21. Four new additions are ACT (AS18209), MNR Broadband (AS133648), Facebook itself (AS63293) which is worth exploring) and GEONET GEOCITY NETWORK SOLUTIONS (AS45235). This actually makes me wonder why I do not see any FNA nodes on my ex-employer Spectra AS10029 as yet.  (30 Aug 2018 Update: I missed this, please see footer below)

  4. In case of Mumbai (or Bombay as used for BOM airport code), the number went up from 17 to 21. New additions HNS (AS38457), Airtel (AS9498) and Vortex Netsol  (AS136334). 

  5. For Chennai number stayed same at 6 (4 telco – Airtel, Jio, Vodafone, IDEA) and 2 broadband ISPs (ACT and Hathway). 

  6. In Kolkata IDEA added the new FNA node. Rest all seems the same. 

  7. I see zero active nodes in Dishnet Wireless (Aircel) now. Earlier there was one in Kolkata and one in Chennai. 

  8. Still zero active nodes in India’s largest govt. incumbent operator BSNL AS9289. They clearly do not understand the value of content caching nodes. 

  9. There’s a major growth in a number of FNA nodes in Airtel from 9 (in March) to 16 (now at the end of Aug). And for IDEA number went from 6 to 12. While the number of nodes in Vodafone stays same (14). 

  10. There’s no node in any of Tata telecom companies. 

Well, that’s all about for now. Have a good Rakshabandhan. 🙂

Update: 30th Aug 2018

My friends from Spectra pointed out that they do have a node and that made me to re-look at my scripts. Due to a bug in the scripts, I was not getting all the nodes. I have fixed the bug and updated the data in this post. 

24 Sep

Tata Communications (AS4755) pushing traffic to Reliance Jio (AS55836) via Singapore!

Bad route

So it seems like apart from voice interconnect issues, Jio is also facing routing issues on the backbone. I ran a trace to one of IP’s on Jio network allocated to end customer –

I ran trace from all Indian RIPE Atlas probes – https://atlas.ripe.net/measurements/5738489/#!probes

There seem quite a few RIPE Atlas probes which are giving latency on 150ms + range. Seems like they are downstream or downstream of downstream of Tata Comm’s AS4755 and routing is happening via Singapore!



Two of such traces

jio1 screen-shot-2016-09-24-at-11-26-05-pm


This isn’t how regular routing should work since even if both do not announce routes to each other, Jio’s routes are visible at NIXI. E.g NIXI Noida shows visible which covers that test IP. Tata AS4755 is probably rejecting that IP.



And if we look at Tata AS6453 routing table for their Chennai PoP, it shows AS_PATH as AS3431 (PCCW Global) who happens to be upstream of Jio’s International network AS64049.



Clearly, that’s just bad routing!


It might be the case Tata is doing intentionally without any evil plans because NIXI might just not have sufficient capacity. Overall ISPs should peer with PNI’s as well as we need IX’es other than just NIXI to promote more peering and promote better interconnect.


Disclaimer: This post and expressed comments are in my personal capacity and my employer has no relation with it.