Belkin Pre-N F5D8230-4 v2, slow video frame rate

Question

Level 1

49 points

Belkin Pre-N F5D8230-4 v2, slow video frame rate

After years of faithful service from my D-Link DI-713P, the wired-ethernet switch (to which my iMac was connected) stopped working. I bought a new Belkin Pre-N F5D8230-4 v2 to replace it, and both the wired and wireless connections work fine... except with iChat. I can get a connection (e.g. to appleu3test01), but the frame rate is painfully slow. Running through the router, I get <15fps, <70kbps. Connected directly to my DSL modem through PPPoE, I get 30fps, >700kpbs; same performance as with my old D-Link router before it croaked. This seems to me to be a clear indication that the problem is the router, not my iMac, the DSL modem, or the ISP (SBCGlobal.net).

Things I have tried to solve the problem.

1. Port mapping all the iChat TCP and UDP ports listed in numerous locations in this discussion group, Apple support, portforward.com, etc.

2. Enabling UPNP with and without the port mapping enabled.

3. Operating through DMZ.

4. Unbind SIP from port 5060 (see Ralph Johns' very helpful site: http://www.ralphjohnsuk.dsl.pipex.com/page4.html#_text). I was not able to telnet into the router (connection refused), and I couldn't find any SIP configuration on the web interface to the router, so I actually didn't get to try this. I don't have VoIP, and I'm not aware that SBC offers it, so I doubt that this is the problem.

5. Ensured that iChat ports are allowed in OS X firewall.

Any of these configurations enable me to make an iChat video connection, but all with slow frame rates.

One other bit of information that might be helpful to someone who understands all this a bit better than I is the entries that are generated in the Belkin firewall security log when I run iChat:

DoS log:
2005-10-16 08:17:59 [HOST Attack: UDP Flood] (UDP) LAN to WAN 192.168.2.2:16384->17.202.39.141:16384 [Drop]
2005-10-16 08:17:59 [HOST Attack: UDP Flood] (UDP) WAN to LAN 17.202.39.141:16384->71.131.221.23:32784 [Drop]
2005-2005-10-16 08:18:00 [HOST Attack: UDP Flood] (UDP) LAN to WAN 192.168.2.2:16386->17.202.39.141:16386 [Drop]
2005-10-16 08:18:00 [HOST Attack: UDP Flood] (UDP) WAN to LAN 17.202.39.141:16386->71.131.221.23:33811 [Drop]

It would seem that the firewall considers the iChat traffic on 16384 and 16386 to be denial-of-service attacks. Shouldn't the port mapping prevent this? If this were the only problem, wouldn't operating in DMZ avoid this problem?

I have not yet tried changing the firmware version of the router, in part because there seems to be some confusion about what the latest version is: web site lists 1.01.03 with a date of September 2005, but my installed version is 2.00.06. Apparently a version 1.01.04 was released but then retracted, and 1.01.03 is from January 2005, not September. Revision control does not seem to be Belkin's strong suit. Right now I have nothing to lose, so loading 1.01.03 may well be my next step.

Some configuration details:

iMac, PowerPC G4 (3.3), 1.25 GHz, 768 MB RAM, 167 MHz bus
OS: OS X 10.3.9 with all security updates as of 2005-10-16
connection method: SBCGlobal ADSL through Speedstream 5260 ADSL modem through Belkin FSD8230-4 router through ethernet to iMac
connection speed: 1214 kbps down, 306kpbs up
software: iChat 2.1 (v153)
camera: Canon ELURA70

Router info:
Firmware Version 2.00.06
Boot Version 1.00.00
Hardware F5D8230-4 v2

Is anyone getting good performance with iChat and this model Belkin router? Any other clever configuration ideas to try?

- Fry -

Posted on Oct 16, 2005 10:19 AM

Reply

Answer 1

Oct 16, 2005 2:37 PM in response to Fry

Hi,

Re 4. It is only Modems that are SIP aware and as you can connect direct through the modem this is not a problem.

I do not know much about Denial of Service but this does seem to be where the problems are.

My understanding is that the DoS works when it thinks there is an attack whether or not it on a port you have specified or not. I believe it works on a specified packet size.

I am not sure if such a size can be altered to get a more successful contact. I cetainly can not find such a setting on my Linksys (but then again I may not have it).

This page is for another Belkin (as yours is not listed on this site). However it does show a WAN Ping Blocking item in the left hand menu and also System Settings at the bottom of the list. I would look at both f these if you have them on your set up pages.

Sorry I can't be of more help.

Ralph

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Answer 2

Fry Author

Level 1

49 points

Oct 16, 2005 5:14 PM in response to Ralph-Johns-UK

Hi Ralph,

Thanks for the reply. I re-read your page on SIP and realize that it was a modem (not router) issue after I posted. Dohh! Thanks for being so polite.

I agree that the DoS seems like the key, and hopefully the specific security log messages will facilitate useful feedback from the Belkin tech support folks to whom I sent a copy of my post.

I tried turning on WAN Ping Blocking - no change. The System Settings tab allows me to set the password, date/time, and enable/disable of remote management, NAT, UPNP, and auto-update for the firmware. Of those I have only switched UPNP on and off. Unfortunately there is nothing on packet size settings anywhere that I could find.

I tossed the packaging for the router, so I may not be able to return it easily. If this is the case, and Belkin (or someone in the forum) doesn't come through with a solution, I was thinking of buying an inexpensive wired router to connect between the modem and the iMac, and also run the Belkin off of the wired router for wireless access. Are there well-known problems daisy-chaining routers like this?

The obvious alternative would be to sell the Belkin (to some non iChat user) and replace it with something known to work well with iChat. I read a recommendation for the Netgear DG834G in another posting, which could also take the place of my Speedstream modem (although there is nothing wrong with it). Any other recommendations from this wise community?

For the time being I am switching between the router routine tasks and direct-to-modem with PPPoE for iChat. Not elegant, not easy to teach to spouse, but it works.

Cheers,

- Fry -

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Answer 3

Oct 17, 2005 3:29 AM in response to Fry

Hi,

James Weston who knows more about networking issues often posts that Speedstream (namely the 5200) seem to do better if set to Bridge mode and let the next device handle the PPPoE login, as a more permanent solution.

The problems with daisy chaining modems and routers when talking about iChat is that it does not like two DHCP servers in line as it creates subnets. Many routers (not the modems) pass all previous IP addresses as well as issuiing their on=wn if in the default state. The Mac displays the IP from the closest but can be getting two IP addresses from the respective devices.

This means that you should set one device to be the DHCP server if that is how you are going to issue IP addresses. Static addresses from one device with the others as Access points/bridges is best. Access points with DHCP and UPnP can be as effective.

It will probably be better if any device is doing the PPPoE then it should also be the LAN IP address device.

Ralph

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Answer 4

Fry Author

Level 1

49 points

Nov 6, 2005 11:42 PM in response to Fry

Long story short - problem solved by replacing Belkin F5D8230-4 version 2000 with an older F5D8230-4 version 1000 router with firmware version 1.00.06. Belkin didn't come right out and say that it was a known problem, but when they shipped the (free) replacement router, it was the old version with the old firmware. I tried updating the v1000 to firmware 1.01.03 (the latest on Belkin's web site for that model), and it also whacked the frame-rate in iChat. Downgrading to 1.00.06 brought things right back to normal.

2ith both routers iChat worked consistently (poorly with v2000, good with v1000) with or without any explicit port-mapping, with UPnP on or off, and with the firewall turned on or off.

- Fry -

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Answer 5

Nov 7, 2005 5:06 PM in response to Fry

HI Fry,

Glad to hear that you found a solution.

There has been another thread here recently where people have reported that going back to older firmware has been the solution.

I have also had a chat this weekend where someone had found a beta firmware version for his Netgear.

Ralph

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Answer 6

Fry Author

Level 1

49 points

Nov 16, 2005 7:50 PM in response to Fry

Well, success with the old revision Belkin router was fleeting. Tried to iChat with my father yesterday, and we could not connect at all. Straight to the DSL modem worked fine. I suspect that something is going squirrely as I have had other connection problems in the past few days.

Today I picked up a Netgear WGR614RVNA, installed it in ~5 minutes, and had iChat working with my mother a few minutes later.

Thanks again, Ralph, for the suggestions and encouragement.

- Alan -

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Answer 7

Nov 17, 2005 2:55 AM in response to Fry

Hi Fry,

Hope this works as a more permanent solution.

Keep an eye on what the ISP says it is doing to your Service.
(VoIP services are the biggest conflict)

Ralph

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