Expert question about UPC 3925 rotuer and bad Skype quality...

100gSoma

Hi all,

I have a 100mb connection with UPC and use their supplied Cisco EPC3925 router.

My issue is that my Skype audio is always broken, and Skype says "my computer is too slow". I have tried it on a brand new 1.66ghz 2gb ram Netbook and a new Laptop with 2.2ghz i7 plus16gb Ram etc. So it is not my laptop or netbook speed.
Speedtest says I get 75mb down and 9mb up. I have not other speed issues with the connection. I thought maybe its my wireless card? I spent weeks troubleshooting and trying to figure out why Skype is a dog on my new fast machines. I wondered was it Windows 7 or was it the audio processor drivers (Sigmatel versus RealTek etc).

Finally I had a breakthrough. I discovered that using my Android phone as a wifi hotspot, I could Skype fine using my PC. Zero audio issues. absolutely perfect. My phone is on O2 and has a data link of maybe 5mb/sec at best. It works perfect on Skype, yet my 100mb UPC connection cannot make an audio/video call on skype without serious broken audio and loss of signal. Hmm... I think it rules out the laptop(s) as the issue as they work fine while connected to my phone wifi.
Do I need to open ports for skype or something on the router? any ideas or suggestions welcomed.

100gSoma

Just wondering... I've been researching online just now and there seems to be a lot of sites talking about port forwarding on Skype. I never even knew that there was a setting for a port for incoming connections on Skype.
I have opened ports before for uTorrent or for games, but not for Skype. could this be the answer to all of my issues! could it be that simple? Open a port exclusively for skype or assign one of my already opened ports to Skype to help improve incoming audio or video streams?
By the way, with all my Skype problems, the people I Skypecall always see and hear me 100% perfectly. It's just me that cannot see them smoothly or clearly or hear them without broken audio. that seems to indicate its an incoming issue not an outgoing one? Again, any suggestions much appreciated.

thanks

roast

You could enable UPNP on your modem, which would bypass the need for forwarding ports.

Before tinkering with settings though, have you tested to see if the issue occurs over an ethernet connection? If all is OK through ethernet, then that indicates just a wireless issue with the modem, in which case your Channel may need to be changed.

100gSoma

Hey Roast, Many thanks for your reply. I'm unsure about UPNP and how it works, but will google it. Cheers.

Regarding trying it with ethernet cable, yep, I tried that. I was thinking it was an old/bad or incompatible driver on my wireless N card. It's the very same when plugged into router via ethernet directly, so I'm guessing it's not a wireless setting in itself.

Will try assigning an open port to Skype, or will look up UPNP too and see how I can maybe use that to avoid using port forwards.

edit -

Had a read up on UPNP. I will check if it is enabled or disabled on my router when I get home.
If I understand it correctly it allows certain devices or software (Skype for example) to automatically request what it needs from the router, such as opening a port for incoming connections. I saw some concerns too about security and some forum posts (they were old posts though 09) stating that Skype did not close the ports it opened upon exit while using UPNP.
I'll read some more, and if this actually does fix my issue, I might just assign one port for Skype and port forward it, rather than enabling UPNP. Will let you know how I get on. Really hope this is the issue. Damn shame I cannot make clear video calls with my new laptop and my 100mb connection. grrr. thanks again for your suggestion.

100gSoma

Well... neither solution worked. Port forwarding or UPNP.
I wonder if I have a faulty router?
As I said, Skype on my PC is fine using my Phone as a wifi hotspot. grr...

DingDong

I have an Cisco 3925 and don't have this problem, try turning off the "SPI Firewall Protection". Do you still have this problem when hard wired to the router?.

100gSoma

Hey DingDong, thanks for your reply. Yes it was the same when hard wired to router. I think I have cracked it though.
I disabled WMM support on the QoS tab in the router menu. It works perfect. Re-enabled, its broken again. Did this several times and did a skype echo test call each time. It's broken with it enabled (which it is by default!). I think thats it! After months of trying to fix it. Thankfully!

DingDong

Hopefully that's it, it's enabled on mine with no issues

100gSoma

DingDong wrote: »

Hopefully that's it, it's enabled on mine with no issues

Yep, that seems to be it alright. Great stuff.

100gSoma

Hey DingDong,

Sorry to bring this up again. I've just realised that my download speeds with WMM support disabled are limited to 10mb/sec (using speedtest.net or upc speed test).
When I enable it, my wireless connection download speeds jump back to 50-70mb/sec as expected but Skype is a dog again.

You said you have 'WMM support' enabled and Skype is fine? Mine will not complete an unbroken "echo test call" with WMM support enabled. Tried 3 different laptops. Once I disable it, perfect quality on all laptops. Perfect video calls, and no break in voice calls etc. Only drawback as I stated is my download speed is limited at 10mb/sec when WMM support is disabled!? Thinking my EPC3925 might be faulty.

100gSoma

I was thinking of buying a new wireless N router, and just disabling wireless in my Cisco EPC3925 and connected the new router to it via an ethernet cable. then just connecting wirelessly to the new router. Would that work? Thinking something like this? http://www.komplett.ie/Komplett/product/routers/80005847/tp_link_wireless_n_router_tl_wr842nd/details.aspx

DingDong

Yeah WMM support is enabled on mine. Did you try turn off "SPI Firewall Protection" under the security tab. I used two different cisco 3925 and had no problem with skype on either. It must be a fault of some kind with your cisco. I wouldn't bother with a new router as I found the Cisco performance the same as my old netgear WNR2000.

100gSoma

Thanks for your reply DingDong. I have not tried turning off "SPI Firewall Protection" no. I will try this tonight. I use Software Firewall anyway, so I think I can try this without any risk and see if it affects the situation either way.
I'll contact UPC and see if I can get a replacement router to try out. It certainly seems to be a router specific problem, and the fact that your Skype worked fine on two other epc 3925s seems to confirm my router might be the issue. I cannot even do the "echo test call" function on Skype without the recording dropping in and out every 2 or 3 seconds. Its that bad with WMM support enabled.
Thanks for the info. Very valuable and much appreciated. I'll let you know how I get on.

update: I just had a call from UPC tech support just now about this issue which I mailed them about earlier. They recommended turning off the firewall too to see if it helps! Fingers crossed. If it doesn't, I've to get back to them. We'll see.

100gSoma

It wasn't the SPI firewall. Finally managed to figure it out.

The issue was that "WMM support" must also be enabled in the Intel(R) Centrino(R) Advanced-N 6230 adapter settings on the laptop too. This setting is hidden away in the Wireless Network Connection Properties under Network Connections. There is a configure button there for the Intel(R) Centrino(R) Advanced-N 6230, and then an advanced tab. In the advanced tab and is an item called Ad Hoc Qos Mode with a WMM enabled/disabled dropdown. It needs to be enabled here aswell as on the router, otherwise Skype etc won't work properly. This 'WMM support' setting is enabled on the Cisco EPC3925 router by default otherwise the connection to any wireless adapter(s) can never go above 54.0Mbps as stipulated by 802.11e standards. However, the setting is not always enabled by default in the Intel(R) Centrino(R) Advanced-N 6230 or equivalent on netbooks or laptops as I have found out. Enabling it on both the router and any network adapters allows for perfect Skype connections and fast speeds. If it's not enabled on one or the other, the problems occur.
Phew... Sounds simple in retrospect but spent many hours troubleshooting that.