I'm using Linux Mint 12 and I have an Asus PCE-N15 wireless card, which is running the Windows driver. Anyway, periodically I completely lose my connection, though Network Manager and iwconfig still claim that it's fine. If I ping my wireless router continually, I get something like the following:
64 bytes from 192.168.1.1: icmp_req=2368 ttl=64 time=132 ms
64 bytes from 192.168.1.1: icmp_req=2369 ttl=64 time=1239 ms
64 bytes from 192.168.1.1: icmp_req=2370 ttl=64 time=1098 ms
64 bytes from 192.168.1.1: icmp_req=2371 ttl=64 time=848 ms
From 192.168.1.119 icmp_seq=2408 Destination Host Unreachable
From 192.168.1.119 icmp_seq=2409 Destination Host Unreachable
From 192.168.1.119 icmp_seq=2412 Destination Host Unreachable
From 192.168.1.119 icmp_seq=2415 Destination Host Unreachable
The connection strength should not be an issue, nor do I believe that the router itself is the problem, as I do not have similar symptoms on any other computers.
Interestingly, the problem seems to be correlated with my usage of the computer. When I'm not making any TCP requests, the continuous ping hums along fine, with an average latency of less than 10 ms. But when I start making requests, the average latency jumps way up and I start getting "Destination Host Unreachable".
For reference here are the outputs of route, ifconfig, and iwconfig. None of these seems to be any different when I'm unable to ping the router.
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
default 192.168.1.1 0.0.0.0 UG 0 0 0 wlan0
link-local * 255.255.0.0 U 1000 0 0 wlan0
192.168.1.0 * 255.255.255.0 U 2 0 0 wlan0
wlan0 Link encap:Ethernet HWaddr 14:da:e9:f2:4b:b4
inet addr:192.168.1.119 Bcast:192.168.1.255 Mask:255.255.255.0
inet6 addr: fe80::16da:e9ff:fef2:4bb4/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:610537 errors:0 dropped:0 overruns:0 frame:0
TX packets:594181 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:511435072 (511.4 MB) TX bytes:81176260 (81.1 MB)
wlan0 IEEE 802.11bgn ESSID:"Network"
Mode:Managed Frequency:2.437 GHz Access Point: C0:C1:C0:53:A9:DA
Bit Rate=144.4 Mb/s Tx-Power=20 dBm
Retry long limit:7 RTS thr=2347 B Fragment thr:off
Power Management:off
Link Quality=51/70 Signal level=-59 dBm
Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid frag:0
Tx excessive retries:0 Invalid misc:14 Missed beacon:0