Help! Slow LAN speed through RT-N66U

[dongwenxuan]

Just got a new RT-N66U and set it up. The wireless is powerful and works fine.

Speed through wireless is 20/5. But the speed through wire connection is too slow, only around 1/0.2. Sometimes even cannot open the speedtest website.

The PC connected to a switch first, then connected to the router. Running 3.0.0.4.354 beta on the router. Tried everything but still remain the same. Tried the old router, got bad wireless connection but wired connection seems normal speed.

Anyone have an idea about this issue?

Thank you all!

 

[kaiguy]

Do you have jumbo frames enabled on the router, by chance? If so, try shutting it off and disabling jumbo frames on any other devices connected to the router. JF seems to cause more problems than any benefit it may have.

 

[RMerlin]

Also make sure you got good Cat 5e or Cat6 Ethernet cables. Older Cat5 cables do not work with gigabit ports.

 

[dongwenxuan]

Do you have jumbo frames enabled on the router, by chance? If so, try shutting it off and disabling jumbo frames on any other devices connected to the router. JF seems to cause more problems than any benefit it may have.

No, it's disabled by default. And I did try to enable it. But not working.

 

[dongwenxuan]

Well, I did try a few things today.

All cables are checked and replaced by CAT 5e. Router reset. Now the WAN/LAN speed could reach 20/5 by using both RT-N66U and old DLINK router.

But some of the network phones don't work properly when connected to RT-N66U. The issue is, all the phones can call outside number and can answer incoming calls. But some of the phones cannot do internal call. Some of the phone can ring, but cannot hear a voice after picked up (internal phone calls).

I replaced the ASUS router by our old Dlink 655. All became normal. Not sure any ASUS setting against our network phone system.
Any possibilities?

 

[dongwenxuan]

Also make sure you got good Cat 5e or Cat6 Ethernet cables. Older Cat5 cables do not work with gigabit ports.

Tried to replace all CAT 5. It seems wired connection problem solved. But the phone system still had problem. Should I RMA the current one?

 

[kaiguy]

Try disabling the SIP helper under Firewall | General.

 

[dongwenxuan]

Try disabling the SIP helper under Firewall | General.

Did that. No improvement.