How to troubleshoot a slow wireless connection (step by step)?

Question

I am looking for a standard approach to troubleshooting slow wireless connections, regardless of what card or wireless router you have. Pings to the gw in a simple network less than 10 ft away should yield 1-2ms max.

Not the case here.

What are the first steps anyone would start to troubleshoot this slowness?

Considering I have the best newest laptop and best newest wirelss router in the world, and the top rated best newest wireless card onboard my laptop.

What would you do first?

Please list in this format:

1. yadda..
2. more stuff...
3. ...more yadda stuff

I will not bore you with what I have tried; I have done the basics, but maybe I can learn something new. So I am open for a simple how-to.

I am using amd64 10.04 LTS.

Here is an example ping I am experiencing:

ping 4.2.2.2
PING 4.2.2.2 (4.2.2.2) 56(84) bytes of data.
64 bytes from 4.2.2.2: icmp_seq=1 ttl=56 time=59.4 ms
64 bytes from 4.2.2.2: icmp_seq=2 ttl=56 time=14.3 ms
64 bytes from 4.2.2.2: icmp_seq=3 ttl=56 time=186 ms
64 bytes from 4.2.2.2: icmp_seq=4 ttl=56 time=115 ms
^C
--- 4.2.2.2 ping statistics ---
4 packets transmitted, 4 received, 0% packet loss, time 3004ms
rtt min/avg/max/mdev = 14.358/93.823/186.334/64.251 ms

---

its been great hearing 1 response, very cool info, i just added more input to persuade you/those viewing that I have done some basics, to assist in response to my quest for a step by step approach to completion.

as for the "garbled pastes, welp, the interface didnt allow me much room to edit it, ex: when i hit the enter key to create a new paragraph, it took that as i was done. so the input methods defined in this page needs a little more tuning i would suggest.

lastly, i am still experiencing slow speeds/varied speeds. therefore I would like more input, possibly from new individuals, second opinions are always welcomed as there are hundreds of cmd utils i have yet to explore for this issue. i can say it might be the frames in ifconfig possible as culprit and documentation points to drivers, as yes, these are broadcom restricted drivers. any wizards about?

i would like to hear from you all, and wish to use this procedure on help.ubuntu as somepoint giving credit where it is due.

Answer 1

1. Check the wireless connection
   iwconfig is the tool for displaying and setting parameters for your wireless card. Below is an example showing a connection to "Your Wireless Network".

   wlan0     IEEE 802.11bg  ESSID:"Your Wireless Network"  
     Mode:Managed  Frequency:2.457 GHz  Access Point: XX:XX:XX:XX:XX:XX   
     Bit Rate=48 Mb/s   Tx-Power=20 dBm   
     Retry  long limit:7   RTS thr:off   Fragment thr:off
     Encryption key:off
     Power Management:off
     Link Quality=49/70  Signal level=-61 dBm  
     Rx invalid nwid:0  Rx invalid crypt:0  Rx invalid frag:0
     Tx excessive retries:0  Invalid misc:161   Missed beacon:0
   

   Some important information shown:

   • Bit Rate which is how fast data is transmitted to your wireless router

   • Link Quality which is a ratio of how strong your connection with the router is. A low number (e.g. 10/70) would indicate that you are either in a noisy radio environment or that your computer is too far from the router to receive adequate power.

     • If you suspect interference from other routers, try iwlist [interface] scanning, where [interface] is your wireless card's device name to see if there are other routers that are interfering with your router's channel, the frequencies at which your computer and the router transmit.

   • For more information check out man iwconfig

2. Check that your network is connected

   $ ifconfig [interface]
   
     wlan0     Link encap:Ethernet  HWaddr 00:00:00:00:00:00  
     inet addr:192.168.1.115  Bcast:192.168.1.255  Mask:255.255.255.0
     inet6 addr: fe80::6ef0:49ff:fe66:6c18/64 Scope:Link
     UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
     RX packets:8104 errors:0 dropped:0 overruns:0 frame:0
     TX packets:7690 errors:0 dropped:0 overruns:0 carrier:0
     collisions:0 txqueuelen:1000 
     RX bytes:5637315 (5.3 MiB)  TX bytes:1698532 (1.6 MiB)
   

   Important information shown in the output:

   • Line 3 indicates that your link is "UP"
   • The second line shows your ip address ("inet addr"), the broadcast ("Bcast"), and the netmask.
   • The third line is used only for ipv6
   • Lines 4-6 indicates TCP/UDP packet statistics. If there are alot of dropped packets here and your link quality is high, the problem is most likely not on your system, but on the router's end.
   • Line 7 shows the total number of bits sent and received over the interface
3. Check the routing tables and your connection from the wireless router. I'm not sure this is in the scope of your question, but it's the next logical step.