Spectranet Youtube Uneven Speeds - Server Issue

sachins

The Bastard Son
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I'm using spectranet in mumbai. I get uneven speeds on youtube. Look below:

This is the speed i get when connected to the bombay cache server

http://img843.imageshack.us/img843/8946/55485545.png

And here is the speed when connected to the bangalore cache server
http://img43.imageshack.us/img43/7320/34202144.png

I have no control over server connections. It connects randomly to either bombay or bangalore. My video streaming experience is mixed. Sometimes I can watch a 1 hour video without interruption and other times, I can hardly watch a 3 minute video.

I don't understand why spectranet sends a mumbai user to fetch his data from a server in banglore.
 

mgcarley

Founder, Hayai Broadband
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6,298
Depends on what the cache has available, perhaps... but out of interest, are you using Spectranet's DNS or some public DNS such as Google's or OpenDNS?
 

sachins

The Bastard Son
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Say I complete watching a video XYZ from youtube with good speeds(ie bombay server). I tried watching that same video(url) again after 5min but I got connected to the bangalore server(ie buffering speed). So its not picking up cached data. In fact, I've tried looking at the most unpopular video urls which nobody in india was likely to have seen... if that video streamed from bombay server, it got through full speed. But if that stream come through bangalore, it would be slow. So youtube mumbai and youtube global have a dedicated pipe between them which they allow spectranet users to share.

I have tried three different DNS servers... opendns, google and spectranet. They don't make any difference. At the moment, I'm trying to find a way to make youtube connect to bombay servers by default instead of bangalore.

I should also mention that I can download apps from android at 1MB/s most of the time. With youtube, its a matter of luck.

----------

EDIT:

I had earlier thought that I was only getting streams through bangalore and mumbai but I guess there are more...

http://tc.v14.cache5.c.youtube.com
http://tc.v11.cache4.c.youtube.com
http://tc.v7.cache1.c.youtube.com
http://tc.v24.cache8.c.youtube.com
http://o-o.preferred.bru02t11.v8.cache2.c.youtube.com
http://o-o.preferred.bru02t11.v4.cache3.c.youtube.com
http://o-o.preferred.bru02t11.v6.cache6.c.youtube.com
http://o-o.preferred.bru02t11.v7.cache7.c.youtube.com

I don't know where "bru" is in india. The first four may not be in india. But again, no problem with speeds from these servers. Only bangalore seems to giving me buffering speeds.
 


mgcarley

Founder, Hayai Broadband
Messages
6,298
Say I complete watching a video XYZ from youtube with good speeds(ie bombay server). I tried watching that same video(url) again after 5min but I got connected to the bangalore server(ie buffering speed). So its not picking up cached data. In fact, I've tried looking at the most unpopular video urls which nobody in india was likely to have seen... if that video streamed from bombay server, it got through full speed. But if that stream come through bangalore, it would be slow. So youtube mumbai and youtube global have a dedicated pipe between them which they allow spectranet users to share.

That is weird... it shouldn't be "switching" half-way through :S

I have tried three different DNS servers... opendns, google and spectranet. They don't make any difference. At the moment, I'm trying to find a way to make youtube connect to bombay servers by default instead of bangalore.


Spectranet should *in theory* be your best bet, due to Youtube being on a CDN and all.

However, due to Youtube being on a CDN, there is no way really that *you* can force it to connect to one particular server - the load balancers in the CDN are choosing that for you based on where it thinks you are located, your route (Most efficient? Lowest Ping? Maybe Spectra has better peering in Bangalore than Mumbai? Maybe some funky routing going on in Spectra's network as a result of some potentially faulty traffic "optimization"? This situation reminds me a bit of the problems that some BSNL users are facing on an erratic basis)...

That being said, I've not observed the same issues on my network - my traffic *always* talks directly to the Mumbai servers, but then, I'm not nationwide yet either, so we'll see what happens later on.

I should also mention that I can download apps from android at 1MB/s most of the time. With youtube, its a matter of luck.

Not being an Android user (yet) I'm less familiar with the topography of the Android market clusters, but given that it uses significantly less bandwidth than Youtube, I'd say there are fewer locations from which it can pick and choose to download and instead of choosing from servers in say Mumbai, Bangalore, Delhi and Chennai like it does for Youtube, maybe it's choosing only between Mumbai and Chennai or something.

----------


EDIT:

I had earlier thought that I was only getting streams through bangalore and mumbai but I guess there are more...

http://tc.v14.cache5.c.youtube.com
http://tc.v11.cache4.c.youtube.com
http://tc.v7.cache1.c.youtube.com
http://tc.v24.cache8.c.youtube.com
http://o-o.preferred.bru02t11.v8.cache2.c.youtube.com
http://o-o.preferred.bru02t11.v4.cache3.c.youtube.com
http://o-o.preferred.bru02t11.v6.cache6.c.youtube.com
http://o-o.preferred.bru02t11.v7.cache7.c.youtube.com

I don't know where "bru" is in india. The first four may not be in india. But again, no problem with speeds from these servers. Only bangalore seems to giving me buffering speeds.

Based on the routes, I don't think any of these are in India. Many CDNs have a habit of using IATA Airport Codes to identify locations - the last 4 I would suggest are in Brussels, of all places.
 

sachins

The Bastard Son
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Matt, I should mention that I use a 256kbps plan. Almost everything works at 256 for me expect for a few sites. One of them being youtube(ie more than 256 plan). Then I later found that android too downloads at unique rates. So Im guessing that spectranet has put dedicated pipes to some popular sites(data servers) located in india.Notice that the bangalore youtube url specifically has the term "spectranet" in it. The others don't. So I guess SN has just one youtube server in india(bangalore). With the other servers, SN may not be putting any speed caps. Maybe that's why most of the spectranet youtube traffic is diverted through bangalore; its only server.
 

mgcarley

Founder, Hayai Broadband
Messages
6,298
Matt, I should mention that I use a 256kbps plan. Almost everything works at 256 for me expect for a few sites. One of them being youtube(ie more than 256 plan). Then I later found that android too downloads at unique rates. So Im guessing that spectranet has put dedicated pipes to some popular sites(data servers) located in india.

Notice that the bangalore youtube url specifically has the term "spectranet" in it. The others don't. So I guess SN has just one youtube server in india(bangalore). With the other servers, SN may not be putting any speed caps. Maybe that's why most of the spectranet youtube traffic is diverted through bangalore; its only server.

Perhaps maybe your situation is more local than that: the bom0Xs0X series is in the same cluster of servers that we hit, so perhaps your cable operator has another upstream provider which doesn't limit connection speeds to Youtube, whereas traffic to Bangalore is getting limited by your plan speed as per Spectranet's specifications - and being that you're in Thane, I wouldn't be surprised if your cable operator works with some of the same people I do (we don't limit Youtube speeds).

I know for a fact that Spectranet is desperate to advance services in Mumbai and were willing to come to some interesting arrangements to do so, so as of now from what I understand, the situation they're in is that unlike some of the other metros, they have a lot less of their own infra in Mumbai than elsewhere.

As for the reason that I suspect that Bangalore is probably being chosen as the next server of choice (for whatever reason) is that it may be the next closest or best performing - the other options would be Delhi (Mumbai-Delhi, much more congested route, so probably doesn't perform as well) or Chennai (Mumbai-Chennai also extremely congested, plus some infrastructure in Chennai is rubbish and causes all sorts of problems).

Maybe do a trace to Bangalore and Mumbai servers and post the results (tracert o-o.preferred.bom03s03.v13.lscache8.c.youtube.com and o-o.preferred.spectranet-blr1.v11.lscache6.c.youtube.com respectively).

Please note: most of this post is theory with a little educated guessing and deduction - although I do know and occasionally speak to the guys at Shyam Telecom/Spectranet, I don't work with or for them nor am I associated or affiliated with them in any other way and am only basing all this on what I know about how my network talks to Google/Youtube/etc.
 


sachins

The Bastard Son
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Bom is not bombay like I thought
Code:
C:\>tracert o-o.preferred.bom03s03.v13.lscache8.c.youtube.comTracing route to o-o.preferred.bom03s03.v13.lscache8.c.youtube.com [173.194.52.112]over a maximum of 30 hops:  1     1 ms     1 ms     1 ms  10.200.XX.XX  2     5 ms     4 ms     4 ms  203.122.52.249  3     2 ms     3 ms     3 ms  203.92.38.25  4     8 ms     9 ms     9 ms  72.14.215.78  5     8 ms     8 ms     9 ms  209.85.242.55  6     7 ms    18 ms    11 ms  173.194.52.112Trace complete.
Blr
Code:
C:\>tracert o-o.preferred.spectranet-blr1.v11.lscache6.c.youtube.comTracing route to o-o.preferred.spectranet-blr1.v11.lscache6.c.youtube.com [203.92.60.206]over a maximum of 30 hops:  1     6 ms     3 ms     4 ms  10.200.XX.XX  2    11 ms     9 ms     9 ms  203.122.52.249  3     7 ms     4 ms     5 ms  203.92.38.25  4    56 ms    53 ms    48 ms  203.92.63.137  5    48 ms    49 ms    50 ms  cache.google.com [203.92.60.206]Trace complete.
 

mgcarley

Founder, Hayai Broadband
Messages
6,298
Bom is not bombay like I thought

Yes it is - this set of servers is in Prabhadevi :)

Code:
C:\>tracert o-o.preferred.bom03s03.v13.lscache8.c.youtube.comTracing route to o-o.preferred.bom03s03.v13.lscache8.c.youtube.com [173.194.52.112]over a maximum of 30 hops:  1     1 ms     1 ms     1 ms  10.200.XX.XX  2     5 ms     4 ms     4 ms  203.122.52.249  3     2 ms     3 ms     3 ms  203.92.38.25  4     8 ms     9 ms     9 ms  72.14.215.78  5     8 ms     8 ms     9 ms  209.85.242.55  6     7 ms    18 ms    11 ms  173.194.52.112Trace complete.
Hop #1 is your cable operator.
Hop #2 & 3 are Spectranet facilities in Mumbai - #2 is still at the cable operator, but hop #3 will be at Spectranet's main Mumbai facility.
Hop #4 is Google's Network... like us, they talk directly to Google. Each ISP that talks to Google will get it's own port (and thus IP address, but in the same IP range), but after that, my hop #5/6 and your hop #5/6 are the same.

Blr
Code:
C:\>tracert o-o.preferred.spectranet-blr1.v11.lscache6.c.youtube.comTracing route to o-o.preferred.spectranet-blr1.v11.lscache6.c.youtube.com [203.92.60.206]over a maximum of 30 hops:  1     6 ms     3 ms     4 ms  10.200.XX.XX  2    11 ms     9 ms     9 ms  203.122.52.249  3     7 ms     4 ms     5 ms  203.92.38.25  4    56 ms    53 ms    48 ms  203.92.63.137  5    48 ms    49 ms    50 ms  cache.google.com [203.92.60.206]Trace complete.
Hop #3 is Mumbai, but unlike the other trace, hop #4 is still Spectranet's network (all the way in Bangalore, by the looks) - the server itself is located in Spectranet's DC and has a Spectranet IP address - it is not on the Google Network, although it may very well be one of Google's server appliances.

On the other hand, connecting directly to Google in Mumbai itself is kind of like "free" bandwidth: Google takes care of the traffic and distribution thereof from Mountain View out to it's branches in each respective country/city, and has a reasonably nice peering policy which makes it reasonably easy for ISPs to connect to them and boost the performance of Youtube and other Google services without spending a great deal of cash.

However, I find it a little odd that Spectranet would be restricting bandwidth within it's own network, but I can see the potential reasoning if it is travelling all the way to Bangalore (probably on a rated connection and not on dark-fiber - that would be a pretty expensive proposition, especially if it's leased)...

Basically, you have 256k, which limits the speeds you get to the Internet according to your plan, but for whatever reason (perhaps the cost, as mentioned) Spectra is not rate limiting speed to Google's Mumbai servers (which is a good thing).
 

sachins

The Bastard Son
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I'm trying to think this from an ISP's PoV. Wouldn't it be a win-win for all if a user from mumbai is sent to mountain view from prabhadevi(PD) instead of mumbai>bangalore>mountain view? Could the cost to get the data from blr be less expensive compared to PD? But you said "free bandwidth" wrt to PD. If it's free then why are they diverting users all the way to bangalore?Either SN engineers are too stupid or too slick.
 

mgcarley

Founder, Hayai Broadband
Messages
6,298
I'm trying to think this from an ISP's PoV. Wouldn't it be a win-win for all if a user from mumbai is sent to mountain view from prabhadevi(PD) instead of mumbai>bangalore>mountain view? Could the cost to get the data from blr be less expensive compared to PD? But you said "free bandwidth" wrt to PD. If it's free then why are they diverting users all the way to bangalore?

I don't think you quite read everything quite right - NONE of what you're seeing is coming from Mountain View on the fly - but if it was, it would be coming in from Google Mountain View or whereever to Google Mumbai on pipes that Google pays for (hence the mention that it's kind of like "free bandwidth").

As far as Spectranet is concerned, they only know 1 thing: that the content is coming from Google's caches. Where the servers are located or how the data gets there is not even a factor for Spectranet, nor does it cost them any differently whether the content is cached in Mumbai or the next nearest set of servers (most likely Singapore) or Mountain View itself - as mentioned, getting the data from it's nearest origin (or indeed, Mountain View itself) is Google's problem and has absolutely nothing whatsoever to do with Spectranet or it's traffic capabilities.

As I also mentioned, the servers you're downloading from in Mumbai/Prabhadevi are in the same cluster as the servers I hit and may include the same physical machine(s) that I or users on several other ISPs hit (assuming the ISP has configured it's routing correctly).

HOWEVER

Spectranet *does appear* to have at least 1 Google Server appliance in it's Data Centre in Bangalore which does all this caching too. Being that this server is in Spectranet's DC on Spectranet's network means that Spectranet does have to take care of all the routing to/from that box, and since you get better performance from a caching server in Google's network than you do in Spectranet's network, it says more about how much bandwidth Google is throwing about in it's network as compared to how much Spectranet is throwing about in theirs.

Either SN engineers are too stupid or too slick.

Exactly the opposite, actually, but it does present you with a funny problem.

This may be a bit difficult to follow, but here goes: although in theory you *should* get brilliant performance from a server on Spectranet's network, you don't, because even if between you and either server is a 1 gigabit line, the factors limiting you from doing so are as follows:

Distance from Mumbai to Bangalore;
The line from Mumbai to Bangalore is probably rated at 1 or 10gbit/s if it's leased - I'm not sure how likely it is that they've got dark fiber between cities;
"Competition" from *all* of Spectranet's users between Mumbai & Bangalore for *all* types of network traffic (including all the Bangalore users traffic demands), PLUS; Spectranet limiting the speed of your traffic on the Mumbai-Bangalore route to the speed of your plan so you get a maximum speed of 256kbit/s/31kbytes per second rather than leaving it unrestricted

WHEREAS

Not only is the distance much less;
From Spectranet to Google Mumbai you're looking exclusively at traffic from Spectranet to Google ONLY, the utilization is lower PLUS;
Unlike the Mumbai-Bangalore traffic, it does not appear to be restricted in speed on that link.

To summarize: Spectranet is doing what it's supposed to for your traffic to it's Bangalore cache, but not for the traffic to Google Mumbai. Why this is, I'm not 100% certain, but that you get 20mbit/s to Google Mumbai is a bonus - if only it were consistent that you were hitting Google's Mumbai DC than Spectranet's Bangalore DC so that your Youtube experience was also consistant.
 

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