How Much Bandwidth is Used For Backgroud Downloads

[NA9D]

Re: How Much Bandwidth is Used For Backgroud Downloads

Here's what I think happens.

Each box opens a port to the mother ship at Vudu and stays in communication with it. This is the only way that your box can be used as a "server" to other peers w/o opening ports in your firewall. The mother ship knows the port and IP for each particular box as each one opens on a new port. The mother ship also knows the content on each box. So when someone rents or buys a movie that you have on a box, the mother ship then begins sending instructions for you to send specific chunks of that movie to the requesting box, etc.

So even though the WAN IP is the same, each port is different so it shouldn't matter.

My biggest concern with 4 boxes is that if each box takes up 100 to 200 kbps of bandwidth and you have 4 boxes, that's 800 kbps. That's going to have to be something we will have to look at and experiment with and it's something that I've never thought of.

In terms of Comcast selling you additional service - it's worth the shot. But keep in mind that they have unsaid limits on their consumer accounts (about 90 gigabytes is the going number). You may want to consider moving the a business account with them. They have promotions a lot of times on business accounts. I just signed up for their 8/1 business service on a 3 year contract. The normal price is about $150 per month. Under contract is was $89.00. No limits on business usage...

You could probably have both a business and consumer account on the same line...

[redwein]

Re: How Much Bandwidth is Used For Backgroud Downloads

So with my load balancing router, I clearly see the background traffic going out over both WANs. The lights are constantly blinking on both of the modems and the router shows 4 "sessions" established over each WAN connection (see below). Does this mean that my box established a connection on each and the Vudu server sees my single box as 2 boxes (different ports, different WAN IPs)? That would kind of defeat the purpose of the load balancing for the background traffic. I'm hoping that it still sees it as one box and is splitting the load.

WAN1:
192.168.1.39:8100 - 24.5.24.80:32835
192.168.1.39:8100 - 66.215.89.116:39695
192.168.1.39:8100 - 69.115.83.65:45372
192.168.1.39:8100 - 96.225.79.8:60004

WAN2:
192.168.1.39:8100 - 76.170.117.219:8101
192.168.1.39:8100 - 204.11.220.32:13201
192.168.1.39:8101 - 204.11.220.32:13201
192.168.1.39:8101 - 204.11.220.83:8100

As long as the load balancing is working, I could add a 3rd WAN. If it isn't, then adding a 3rd WAN would do nothing for the background traffic but it would help the download when I buy or rent a movie.

[redwein]

Re: How Much Bandwidth is Used For Backgroud Downloads

Actually, after looking at my last post, each of the "sessions" is to a different destination IP address. I'm guessing that only one of those is the Vudu server. That would suggest that the load is being balanced. Am I understanding that correctly?

[Greg]

Re: How Much Bandwidth is Used For Backgroud Downloads

Hi redwein,

I'm not sure how your load balancer is configured, but from my knowledge of the protocol, it would be best if each box had an immutable WAN associated to it.

For instance, you could have Box 1 and 2 -> WAN 1, and Box 3 and 4 -> WAN 2 as a fixed set of rules.

Given your description of the level of service you have on both (DSL: 6Mbps, Cable: 8Mbps), I don't really think this is going to be a problem.

-- Greg

[redwein]

Re: How Much Bandwidth is Used For Backgroud Downloads

I was thinking of doing that and may end up doing so, but I want to experiment with letting the router decide initially. The router configuration is set up to fix each session (source IP to destination IP) on the same WAN, so there shouldn't be any issues with the session to the server getting messed up by switching WANs. I'm assuming that all of the other communication for the file sharing will be to other IP addresses and load balancing could really help out there, especially if the load requirement isn't static.

The only thing I could see being an issue is if Vudu saw my box as 2 boxes and thought both could independently be used for providing content to other boxes, thus doubling my upstream traffic. My gut feel is that, since the communication to Vudu should be fixed to a single WAN (both should always have the same source and destination IP), this shouldn't be an issue.

The reason I want to keep the automatic load balancing is that I also have 6 PCs and 4 Tivo Series 3 boxes that use the network as well. It would be really cool if everything just gets nicely spread across both WANs. If I'm convinced that it theoretically works well but the overall bandwidth of all of my devices is too high, I will probably add the 3rd WAN.

[Greg]

Re: How Much Bandwidth is Used For Backgroud Downloads

I think I understand what you're trying to do, but unfortunately it will confuse the VUDU protocol and cause connection problems. Some of these will be recoverable (and will only cause network resource thrashing), but others may be more fatal.

I really recommend against using this approach if you can. Instead, a fixed mapping from box to WAN interface plus some QoS rules should give you the flexibility you want/need.

Cheers,

-- Greg

[RonV]

Re: How Much Bandwidth is Used For Backgroud Downloads

I do have a question about your bonding of two WAN connections. Are these connections going to two separate service providers or one that rebonds the connection back to one public IP address?

In the ATM and ISDN world we tend to configure multilink connections with private addresses and then route them out with a single public IP address when they hit the internet. I have done this with many companies that usually get overcharged for anything over a T1....expecially in a rural area.

So with my load balancing router, I clearly see the background traffic going out over both WANs. The lights are constantly blinking on both of the modems and the router shows 4 "sessions" established over each WAN connection (see below). Does this mean that my box established a connection on each and the Vudu server sees my single box as 2 boxes (different ports, different WAN IPs)? That would kind of defeat the purpose of the load balancing for the background traffic. I'm hoping that it still sees it as one box and is splitting the load.

WAN1:
192.168.1.39:8100 - 24.5.24.80:32835
192.168.1.39:8100 - 66.215.89.116:39695
192.168.1.39:8100 - 69.115.83.65:45372
192.168.1.39:8100 - 96.225.79.8:60004

WAN2:
192.168.1.39:8100 - 76.170.117.219:8101
192.168.1.39:8100 - 204.11.220.32:13201
192.168.1.39:8101 - 204.11.220.32:13201
192.168.1.39:8101 - 204.11.220.83:8100

As long as the load balancing is working, I could add a 3rd WAN. If it isn't, then adding a 3rd WAN would do nothing for the background traffic but it would help the download when I buy or rent a movie.

[redwein]

Re: How Much Bandwidth is Used For Backgroud Downloads

I do have a question about your bonding of two WAN connections. Are these connections going to two separate service providers or one that rebonds the connection back to one public IP address?

It's 2 separate providers. One is AT&T DSL and the other is Comcast. The router I'm using is the PePLink Balance 30 (http://www.peplink.com/soho-multi-wan-routers/). I've been thoroughly impressed with it. It has done a great job of load balancing and I have had no problems with things like accessing my work machine using VPN or running multiple game sessions from various PCs or our XBox360. It always seems to do the right thing and doesn't drop any "session" connections. I tried a couple of other routers and they all had problems in those areas.

[redwein]

Re: How Much Bandwidth is Used For Backgroud Downloads

I really recommend against using this approach if you can. Instead, a fixed mapping from box to WAN interface plus some QoS rules should give you the flexibility you want/need.

Thanks for the suggestion. I will definitely do that at the first sign of trouble. I would define trouble as any apparent malfunctioning of the box or unexpectedly high network utilization. Would there be some other problem I should be concerned with? I don't seem to be seeing either of those with my single box and my current load balancing setting. Would the confusion begin with adding the second box? Would you still be concerned if, with multiple boxes, everything looked like it worked fine and the network utilization was right where it is supposed to be? There shouldn't be any hardware damage that this could cause.

[RonV]

Re: How Much Bandwidth is Used For Backgroud Downloads

Ok great thanks for the info. Based on this its not bonding as I thought. Its it seems to have some intellegence based on a combination of the MAC address and the port address that identifis what link the application is bound to. As they call it session bonding.

If you were to bond / aggregate two seperate vendors internet connections for the same application there would be problems with multiple IP's being presented to the hosted service. I have seen this happen with folks setting up Cisco equipment to do aggregation and can't figure out why their mail servers have random connection failures.

I could see using this type of box for a backup if my DSL goes down and using a Linux or Windows box with dialup back to AT&T in this case. Its a bit pricy though...

It's 2 separate providers. One is AT&T DSL and the other is Comcast. The router I'm using is the PePLink Balance 30 (http://www.peplink.com/soho-multi-wan-routers/). I've been thoroughly impressed with it. It has done a great job of load balancing and I have had no problems with things like accessing my work machine using VPN or running multiple game sessions from various PCs or our XBox360. It always seems to do the right thing and doesn't drop any "session" connections. I tried a couple of other routers and they all had problems in those areas.

[Greg]

Re: How Much Bandwidth is Used For Backgroud Downloads

Thanks for the suggestion. I will definitely do that at the first sign of trouble. I would define trouble as any apparent malfunctioning of the box or unexpectedly high network utilization. Would there be some other problem I should be concerned with? I don't seem to be seeing either of those with my single box and my current load balancing setting. Would the confusion begin with adding the second box? Would you still be concerned if, with multiple boxes, everything looked like it worked fine and the network utilization was right where it is supposed to be? There shouldn't be any hardware damage that this could cause.

Actually, issues due to this setup will be present with 1 box only already (it's the fact that the same STB can be "seen from the world" as having 2 diffent public IPs that causes trouble). It will not damage any hardware.
Potential impact is the following: inability to access the service at all, difficulty in streaming a movie (hitting the "end of buffer" condition), difficulty in receiving updates (new movies added to the catalog, etc...), network thrashing potentially triggering DoS protection mechanisms (which can then trigger more drastic symptoms), slower user interface... These are subtle because everything seems to "just work", but bite you in unexpected ways.

I would still be concerned if "everything looks like it works right", because looks can be deceiving - only trained professionals can make this assessment . What I'm concerned about is not what it looks like, it's what's happening under the hood, and its impact on the network.

If _I_ had your setup, I'd determine which of the 2 WANs has the best (i.e. lowest) latency, and then use that one with QoS for services like VoIP and games (I am told that a higher ping time makes the difference between fragging and getting fragged ), then hookup the VUDU box(es) to the other one.

-- Greg

[redwein]

Re: How Much Bandwidth is Used For Backgroud Downloads

Sorry for asking so many questions but I'm just trying to understand this. I really appreciate your answers and I hope you aren't getting frustrated with me. As you can tell, I like new technology and I want to make sure that I am utilizing all of the capabilities available to me, though in a supported way. I am a software architect myself, though not in the area of networks, so I am trying to create a mental image of what Vudu is really doing under the covers and how that meshes with my setup.

I agree that if box B on the outside sees my box A, on my LAN, with 2 different public IP addresses, that would cause a problem. But my router will route all of the communications between my box and any other particular box on the outide, using the same WAN. So, for the duration of that box to box communication session, it will look like its IP is fixed. That is necessary for a whole lot of things to work, like VOIP, online gaming, etc. I have had zero dropped connections when doing any of those things, so I think that is pretty rock solid on this router.

Now the Vudu can't be assumed to have a static IP forever, since most broadband accounts use DHCP, so that public IP address can change over time. Clearly, this scenario had to be accounted for. It seems like, with my setup, the IP may change between sessions between 2 different boxes, but never in the middle of one. It seems logically like the same thing as DHCP changing the public IP after a modem reboot or otherwise.

[Greg]

Re: How Much Bandwidth is Used For Backgroud Downloads

Hi redwein,

I am not getting frustrated with your questions at all, but I know I am getting close to the line that I can't cross without disclosing too much about how the protocol works.

I do know that DHCP can assign a different IP address for you, but most providers will actually keep giving you the same address as what you had when the time comes to renew your lease (in DHCP terminology). This means that your IP will usually not change very often.

The setup you describe with the load balancer is akin to having DHCP change your IP very very frequently (possibly multiple times a second).

I hope this helps.

-- Greg

[redwein]

Re: How Much Bandwidth is Used For Backgroud Downloads

Fair enough. I understand that you aren't at liberty to disclose the details. I appreciate what you have been able to tell me though. Thank you very much.

[redwein]

Re: How Much Bandwidth is Used For Backgroud Downloads

Potential impact is the following: inability to access the service at all, difficulty in streaming a movie (hitting the "end of buffer" condition), difficulty in receiving updates (new movies added to the catalog, etc...), network thrashing potentially triggering DoS protection mechanisms (which can then trigger more drastic symptoms), slower user interface... These are subtle because everything seems to "just work", but bite you in unexpected ways.

Sorry, but I had one more thought on this. Every one of the problems you describe would fall into one of the problem categories that I described. Difficulty streaming a movie, receiving updates and slow user interface would all be in the "not working fine" category. Network thrashing would show up in the "unexpectedly high network utilization" category. I agree that if I saw any evidence of anything like that (my eye isn't completely untrained), I would believe the load balancing was the culprit, not the Vudu box. My first course of action would be to follow your advice.

I actually had those types of issues on 2 other routers that I tried and took the steps that you suggested to fix them and they did work for the most part, though I continued to have intermittent problems with them. I bought this particular router beause it was supposed to be much better at those things and haven't had to make any of those type of configuration changes, at least not yet. It has worked flawlessly.

Also, I just checked my router's status logs. The sessions that I posted in my earlier message are, for the most part, still there and on the same WAN as they were, so I don't think there is much chance of the IP changing frequently at all, let alone multiple times a second. Also, like I said, if that were to happen, VOIP, VPN and online gaming would all be toast.