Internetspeed is reduced to 10mbit/s when using a router

[neijy]

Hi,

I have got a problem with my internetspeed, maybe caused by a LAN to WAN bottleneck. I have cabel internet with 30mbit/s down- and upstream. The only hardware that I received from my ISP is a Cisco SPA122, which seems to be a ATA and not a modem (or is that the same?). The SPA122 has one WAN and one LAN port. According to Cisco it even has an integrated router, but I suppose that it is configured in bridge mode. But I cannot access the SPA122, as I don't have the login name and password. When I connect my computer directly to the SPA122s LAN port my internetspeed is about 30mbit/s. But when I use a TP-Link TL-WR841N as a router the speed drops to only 9,7mbit/s (downstream is constantly 1,2mbyte/s) and upstream is not as constant but also in the area of 10mbit/s. By the way, I am using the router wired only, i.e. WLAN is turned off. First I thought the problem is that the router can only handle 10mbit/s WAN to LAN throughput. But according to TP-Link it has a WAN to LAN throughput of 94mbit/s. To test my router I followed the instruction presented here:
how to test a wireless router
connecting one machine to the lan port and one to the wan port. the machine on the lan port has been set as DMZ.
With netio I measured LAN to WAN throughput of about 10 to 11mbyte/s, which is close to the manufactureres 94mbit/s.
Therefore the router should be able to handle 30mbit/s easily.

What else could cause the internet speed to drop, when the WAN to LAN throughput of the router is fast enough?

Another question what I do not understand is, that when I connect a switch to the SPA122 without a router, every computer connected to the switch actually has internet, with full speed. But every computer then has its own internet IP, I thought the ISP will allow max. 1 IP adress and that is why I need a router, which translates the private IP adresses of several computers to one IP adress?

Thanks for your help!

 

[thiggins]

You need to get a router between your devices and the Internet. Anything with a public Internet IP address is under constant attack. So your computers may soon be compromised if they are not already.

It sounds like your WAN port is operating at only 10 Mbps. What are you using for a modem?

 

[neijy]

Thanks for your request.

Of course I am using the router, because of exactly the same reason you stated. I was just wondering why it would work without a router.

I actually don't know what kind of modem I have. The only hardware I got from my ISP is this Cisco SPA122. There is probably a modem for all flats of the building in the basement, but I dont have access to that room.

That is what I thought, that the WAN port of my router is running at only 10Mbps, but why? I tested the WAN to LAN throughput and is was about 80 to 88Mbps..

Is it possible my ISP has some setting which causes the router run on 10Mbps?

 

[thiggins]

Of course I am using the router, because of exactly the same reason you stated. I was just wondering why it would work without a router.

Sorry. That was not clear from your post.

I actually don't know what kind of modem I have. The only hardware I got from my ISP is this Cisco SPA122. There is probably a modem for all flats of the building in the basement, but I dont have access to that room.

That is what I thought, that the WAN port of my router is running at only 10Mbps, but why? I tested the WAN to LAN throughput and is was about 80 to 88Mbps..

Is it possible my ISP has some setting which causes the router run on 10Mbps?

It is likely an incompatibility between what the building is using to distribute the Internet service and the TP-Link router that is causing the link to be 10 Mbps.

What are the IP addresses you are getting when you connect multiple computers via a switch? If they are private IP it could be that your building has its own router and that is why you are getting multiple IP addresses.

 

[neijy]

When I am using the switch without the TP-Link, then the computer gets the IP address e.g. 94.135.203.207. I think this is a public IP adress, isnt it?

So you think I should just try another router and hope that it works? Have you experienced other cases where an incompability between a router and a modem reduces the internet speed?

Thanks for your help!

 

[thiggins]

Yes, that is a public IP address.

Before you try another router, try putting the switch between your building Internet connection and the router WAN port.

Yes I have seen link auto negotiation problems before.