QoS worth it?

Straz

Straz

Straz

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Joined
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Location
Oxfordshire
Hi all, I currently have a BT homehub 3 on 8mb ADSL with unlimited data usage.

There are 3 PC users in the house, one of which is a power user, his net usage is generally a) video skype b) torrenting c) uploading... You get the picture.

The other is mainly just constant netflix in the evening.

That leaves me trying to play games with pings anywhere from 50-1000, obviously on the top end of the scale when other users are connected. Basically unplayable and leaves me twiddling my thumbs.

My networking knowledge is shady at best, but from my understanding buying a router with QoS isn't going to totally solve the problem. Limiting the outbound traffic could solve the issue of uploading. But it can't limit the inbound traffic coming directly from the ISP as it still has to deal with the data packets.

Is there a way around this? Not sure how well those routers with QoS monitoring on inbound traffic work, can't see it working too well.

The other option is to buy another phone line and set up another connection for that line, but that is the costly option.

Some advice would be greatly appreciated.
 
AFAIK the decent QoS options are limited to cable routers. This doesn't make it impossible for ADSL, but it's additional hassle and expense if you need an external ADSL modem.

An 8Mbit connection is always going to struggle shared between three active users.

Torrenting should obviously be avoided during the evening when people are actively using the connection, and bandwidth limited at other times. It's antisocial not to, but is down to the user to configure.

Personally I'd get my own connection. If a recent thread is to be believed PlusNet will provide a line and standard broadband without requiring a long-term commitment.
 
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Straz said:
That leaves me trying to play games with pings anywhere from 50-1000, obviously on the top end of the scale when other users are connected. Basically unplayable and leaves me twiddling my thumbs.

My networking knowledge is shady at best, but from my understanding buying a router with QoS isn't going to totally solve the problem. Limiting the outbound traffic could solve the issue of uploading. But it can't limit the inbound traffic coming directly from the ISP as it still has to deal with the data packets.

Is there a way around this? Not sure how well those routers with QoS monitoring on inbound traffic work, can't see it working too well.
Click to expand...

Even with a decent Cisco box and good knowledge of Qos this would be a pain, the problem with DSL is that when you're gaming - the tiny udp packets (64-70 bytes) get held up by the bigger data packets (1460 bytes) exiting/entering the DSL interface, which will cause a lot of Jitter, even with advanced QoS and congestion avoidance it's difficult to achieve with ADSL.

Torrenting is even worse on small home-routers because the amount of connections will really hammer the router's memory and nat table..

Basically get your own connection..
 
Well thanks for the replies, I thought as much. Looks like a 2nd line it is. Luckily already had one installed a few years back so should reactivate that and save on the setup cost. Cheers guys.
 
New line ordered with Plusnet, talktalk wasn't available in my area as they hadn't upgraded the switch board.

£25 total a month not bad for lag free internet.
 
"FTTC status: Calendar Year 2014"

I didn't think it would be as soon as this year, if so then all the better. Good thing I only got a 12 month contract out!
 
With TCP packets you also have the acknowledgment packets.

With a regular non QOS router, an upload (or download) can give 100% utilization. What then happens is the acknowledgment packets are delayed holding up the download (or upload).

In other words, if someone is doing a full upload (P2P for example), when you do your regular internet surfing, even even though you are only downloading, the download is slow as the acknowledgment packets are fighting for contention.

My Draytek 2860n has an option to give priority to acknowledgment packets preventing the above situation.

The Draytek 2860n can separate internet usage into class's. So if there is 3 people using the internet their computers can be given 1/3 internet. So if your on a 8mbit connection, you would always have the equivalent of 2.6mbit, that's providing there is no contention on the line to start.

So using something like the Draytek 2860, you can have fast ping times regardless of what anyone else is doing, but it will never be as good as your own connection.

Another advantage of the Draytek 2860 is it can handle multiple internet connections. You can set what computers use what, and if a connection dropped all computers can be switched automatically to the remaining connection.
 
I've not tried it to see how effective it is but you can also get semi-managed switches with QoS functionality i.e. Netgear ProSafe GS105e (note the e - non-e is unmanaged).

Probably more useful for balancing out bandwidth availability rather than gaming traffic priority though.

TBH though the main problem is probably the torrent client sitting there 24x7 cycling connections never mind the bandwidth use as this hammers most routing hardware.
 
There is a software option called cFOS that provides software QOS, you can get this free if you own a Gigabyte motherboard. The software has the ability to communicate between all machines and it can reserve bandwidth for VOIP/gaming.

Rroff said:
TBH though the main problem is probably the torrent client sitting there 24x7 cycling connections never mind the bandwidth use as this hammers most routing hardware.
Click to expand...

The Draytek 2860n can handle 50,000 simultaneous NAT sessions. There is also an option that if a single IP has more then a certain number of NAT sessions open, you can assume it's using P2P and the router can limit bandwidth.
 
JasonM said:
Yes I totally agree, it was worth mentioning as it could 70% solve the issues. For 100% fix OP needs a separate connection however.
Click to expand...

TCP Ack prioritization won't really help real-time traffic tbh,

The problem is that the OP's real-time traffic (gaming) relies on a low-bandwidth steady stream of tiny udp packets, (like a voice call)

When somebody kicks off a download or P2P traffic, the interface will become congested with large packets - these take time to put on the wire because they're larger, meanwhile the smaller real-time packets have to wait in the buffers, this causes jitter and packet-loss to the real-time traffic.

By prioritising TCP acknowledgements, all you're going to do is ensure TCP transfers don't slow down due to ack-latency or tail-drop, but that doesn't help his real-time gaming traffic.

The only way QoS would help real-time traffic is if you were to implement a strict priority-queue for the real-time traffic, but on an 8Mbit DSL connection you're still going to have problems with different packet sizes.
 
V-Spec said:
TCP Ack prioritization won't really help real-time traffic tbh,
Click to expand...

Partitioning the bandwidth into classes, so each of the 3 users is guaranteed at least 1/3 of bandwidth, regardless of whats the other users are doing, this would have helped VOIP / gaming traffic greatly.
 
JasonM said:
Partitioning the bandwidth into classes, so each of the 3 users is guaranteed at least 1/3 of bandwidth, regardless of whats the other users are doing, this would have helped VOIP / gaming traffic greatly.
Click to expand...

On an 8Mbit DSL connection with a 512-800Kbps upload, by the time you've divided that three ways you're left with such small amounts of bandwidth, it simply isn't worth it, and this still doesn't mitigate the problems caused by large packets and small packets sharing the same tiny egress buffers on a DSL interface.

Even on something like a Cisco 1921 with the most advanced and modern congestion management features - it's almost impossible to get this stuff working to the point where it's providing any real benefits, especially on DSL circuits with tiny uploads.

If the OP had a 10Mbit Ethernet link - then yes, because of the Nature of Ethernet compared to a low-speed DSL POTS interface, you could develop a far more effective QoS policy, but with a 512-900Kbps upload, forget it imo.
 
JasonM said:
There is a software option called cFOS that provides software QOS, you can get this free if you own a Gigabyte motherboard. The software has the ability to communicate between all machines and it can reserve bandwidth for VOIP/gaming.



The Draytek 2860n can handle 50,000 simultaneous NAT sessions. There is also an option that if a single IP has more then a certain number of NAT sessions open, you can assume it's using P2P and the router can limit bandwidth.
Click to expand...

Problem is you get connections that get stuck in FIN_WAIT states (common unix/linux issue) and after awhile it degrades performance regardless on most routers.

Unless you've got Annex-M and a good sync it can be difficult with ADSL - though not quite as difficult as some make out IMO.
 
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