08 Nov

Why airport wifi sucks?




Sitting at Kolkata airport. Noticed the usual “Free Wifi in the area!” message and connected to Tata Docomo Free wifi. Performance was quite poor.


Two key issues with wifi: 

  1. Using of only 2.4Ghz (802.11b/g/n with 20Mhz channel). No AP with 5Ghz box. (Click here to view scanner data). Should have been 5Ghz
  2. Entire traffic is getting tunnel via Mumbai i.e West India (while I am sitting on Eastern side). Adding up to latency and performance significantly.


Here are some of traces to random locations:




So no matter wherever I push packets for, then hit hop 5 – Mumbai / VSNL AS4755 router because likely that is where the core L3 device (MSC/central authentication box) for this network is. This is big issue because likely Tata Docomo would be tunneling entire wifi traffic from anywhere in India, going to anywhere globally via Mumbai because that is where they put their wifi central box. What we need in India is more simpler deployments, more open source stuff so cost doesn’t becomes point of selection for keeping such devices central. And most important we need networks to peer at internet exchanges so atleast East region traffic stays within East and doesn’t has to travel thousands of kilometers to Mumbai just to hop on to another network.



Overall speeds seems to be capped at 1Mbps which is too low these days and here’s 100 packet ping to first hop ( showing how poor is the wireless signal performance.


Since latency min is 48ms, quite clearly L3 end is far off in Mumbai and likely would be running ipsec or some other kind of VPN tunnels to the APs. This is ground level performance of what we hear in media “wifi business strategies“. Wifi as a technology is excellent but does take decent homework to deploy properly. Just hanging bunch of boxes and routing traffic from one MSC/central server placed far off doesn’t really helps. Wifi as a technology can help to offload stress on 3G/4G significantly as long as it is done in right way keeping in assumption that Wifi runs on “unlicensed spectrum” and interference can very much happen.

Time to catch up flight to next hop!

13 Jan

Experience with MNP in Haryana

Recently lucky mobile users in Haryana got MNP i.e Mobile Number Portability.

I too ported my number out from Airtel to Tata Docomo. Reason remains the super slow GPRS network (yup gprs, not even upgraded to EDGE in most of Haryana) and crazy service activation followed by irritating sms’es.

Here’s my experience with MNP:

It took around 20 days in porting of my number, and technically speaking – process is yet not (hundred percent) completed even after a month!

One of the problems with system is that whenever one requests for a porting code, it is valid for 15days. If we request for porting code again (via sms) we get same code, with same validity. In my case, I request for code, but I submitted documents for porting after 13days of my initial request. On the day of submission, I requested for code again, and got same code which was expiring after 2days. I did informed retailer about it, but he had no clue. Eventually I submitted form. Next, documents reached company by 16th (or to the middle guy), and they triggered request for porting on 16th day with same old code.

Result: Port out request failed, because porting code was expired!

It took me over a week to realize that, and eventually I submitted documents again. I submitted documents on Monday, and on a fine thursday evening I realized that I didn’t got any call or sms that day! Later, I found I was even not able to send any sms. Outgoing calls were going fine via Airtel connection.

I got clue, and tried using Tata Docomo sim card, and it worked!

All was OK other then fact that I was not able to recieve calls from Airtel users on Tata’s sim. Callers were getting message – “The Airtel number you have dialed is switched off!”

At this point of time I realized a big problem – due to some bugs in system, new carrier actually accepted my number, while Airtel has yet not ported out my number. Good was that I started getting calls even from Airtel users within a day. Logically speaking all was going OK, other then fact that my Airtel connection still works for outgoing, and even at the time of blogging (after a month of porting) it’s still up!

Tata Docomo customer support has no clue about it while Airtel support always requests me to visit Airtel relationship center to get this fixed. (Why really? Can’t they do this ONLINE?!)

Here’s few points about MNP based on my experience:

  1. 15 day rule can be problem.
    As said above – if one submits docs for porting after 13-14days of initial request of port code, there are chances of rejection of request, as it normally takes 2-3 days for request to be registered in system of new operator, and technically initialization of request.
  2. During middle period there is NO WAY to find the status of porting. I have transfered various domain names from various registrars to others, and it is very good that one can get real time step-by-step status of that. It makes absolutely no sense in implementing MNP in such dark manner.
  3. Apart from latest online status, I expect there should be clear norms about who is going to provide support to end user during period. Both carriers – Airtel and Tata Tele’s customer support informed me that they don’t have any mechanism of looking into a number’s detail about porting and only way in case of trouble is to visit company office. That’s just crazy!  Again, this is not a DSL link problem that one needs to visit central office to get line fixed. Even at those offices there are NO technical persons. They are again company support representatives who sit in front of a terminal. Incase of any technical glitch, they can’t do much other then escalating it to technical team, which goes via few “in-house” engineers, before getting off to external outsourced team of equipment vendors.
  4. Based on the way it’s going – in Haryana MNP is causing huge subscriber loss to BSNL and Airtel. Gainers are usually Tata Docomo, and Aircel. I think launch of MNP in rest of India will probably get delayed. Reason remains with the incumbent private carriers.
  5. As of now there are no plans for inter-circle portability i.e you can port number only within a circle, and not out of telecom circle. So if you move from NCR circle to say Bangalore in South India, you can’t port out your number.
    “Technically very hard to implement” – claimed by one of telecom guys. Reality – telcos love roaming 😛

And yes, now I am one of the “3G user”  in India!

and here’s a quick speed test:

Will be posting my experience with Tata Docomo 3G in other post.

Thanks for reading.