Re: Network latency, TCP, Bluetooth
Re: Network latency, TCP, Bluetooth
- Subject: Re: Network latency, TCP, Bluetooth
- From: JP May <email@hidden>
- Date: Thu, 03 Mar 2011 23:54:37 +0100
Sadly this seems to be a well-known nuisance :-/
1. did you try the trick of CONTINUOUSLY SENDING some sort of ping, a tickle to keep everything active?
(build a testbed for your situation and tune it, to find what seems to be the best values for how frequently to send a tickle... what about 2 hz to begin with?)
it could work for you.
2. I fear everyone just has to tell their customers: "Here's a networking tip for iOS devices. For extreme performance, if possible turn off bluetooth when using wifi..." Many real-time games (and the like) have that sort of warning.
3. If anyone has any more up-to-date info now that 2011 is here, fantastic.
On 3 Mar 2011, at 23:46, Arnold Smith wrote:
> I have a client/server app with the server running on OSX and the client running on an iPad. I'm using TCP over wifi for communication. It's an interactive app, so I set TCP_NODELAY on the socket to ensure prompt delivery of the messages between the client and server. This ensures the user gets a smooth response from the app. However, on some iPads (one of six here in the office and a small percentage of our customers) there is an annoying bundling of packets. We use small messages, but on these few iPads, some of the messages (not all) are bundled into large packets, leading to a delay in the delivery of the messages and a jerky response in the iPad app. It's almost as if TCP_NODELAY was not set, but in the extreme: the latency when the packets are bundled is usually over 600 msec.
>
> I can't see anything special about the few iPads that exhibit the problem. But I do know one thing: turning off Bluetooth on those iPads solves the problem! I have no idea what Bluetooth would have to do with this.
>
> I'd rather not have to instruct customers to turn off Bluetooth. Anyone ever see anything like this before? I saw a recent thread about Bonjour possibly causing a problem like this, but the problem persists even if I don't use Bonjour.
_______________________________________________
Do not post admin requests to the list. They will be ignored.
Macnetworkprog mailing list (email@hidden)
Help/Unsubscribe/Update your Subscription:
This email sent to email@hidden