Ping and throttling issues with Huawei E367

[James Bond 007]

I have a Huawei E367 21Mbps HDSPA+ modem in an Asus WL500gp v2 and the koppel.cz firmware. I'm noticing two strange things:

1. Ping to the router is fine (under 10ms) but pinging outside is very erratic from 40ms to 800ms, sometimes even packet loss. The strange thing is that this happens only over a Wi-Fi connection, using my hardwired desktop computer or plugging the 3G modem directly to my laptop results in stable ping around 40-50ms.

2. The download speed was throttled, I have managed to boost it by specifying a higher maximum packet size, but the upload speed is still throttled at 0.59 Mbps according to speedtest.net (dozens of tests return this same value).

Any tips are appreciated.

Some pings for the first problem:
Reply from 217.20.130.97: bytes=32 time=44ms TTL=59
Reply from 217.20.130.97: bytes=32 time=43ms TTL=59
Reply from 217.20.130.97: bytes=32 time=41ms TTL=59
Reply from 217.20.130.97: bytes=32 time=37ms TTL=59
Reply from 217.20.130.97: bytes=32 time=45ms TTL=59
Reply from 217.20.130.97: bytes=32 time=883ms TTL=59
Request timed out.
Reply from 217.20.130.97: bytes=32 time=599ms TTL=59
Reply from 217.20.130.97: bytes=32 time=446ms TTL=59
Reply from 217.20.130.97: bytes=32 time=1325ms TTL=59
Reply from 217.20.130.97: bytes=32 time=2142ms TTL=59
Request timed out.
Reply from 217.20.130.97: bytes=32 time=106ms TTL=59
Reply from 217.20.130.97: bytes=32 time=1732ms TTL=59
Request timed out.
Reply from 217.20.130.97: bytes=32 time=227ms TTL=59
Request timed out.
Reply from 217.20.130.97: bytes=32 time=45ms TTL=59
Reply from 217.20.130.97: bytes=32 time=986ms TTL=59
Reply from 217.20.130.97: bytes=32 time=884ms TTL=59
Reply from 217.20.130.97: bytes=32 time=871ms TTL=59
Reply from 217.20.130.97: bytes=32 time=559ms TTL=59
Reply from 217.20.130.97: bytes=32 time=1402ms TTL=59
Reply from 217.20.130.97: bytes=32 time=2046ms TTL=59
Reply from 217.20.130.97: bytes=32 time=246ms TTL=59

[wpte]

3G internet always has an unstable high ping...
not too sure about packet loss.

Does it work a whole lot better when used in your pc?

[James Bond 007]

Does it work a whole lot better when used in your pc?

The ping is much more stable in the PC, but I feel no difference in website responsiveness, even with the bad pings, everything is very fast.

Just realized problem #3 tonight: download speed is also throttled at around 500 KB/s with packet size 4096. Tried to raise it to 8192, no change. Attached a chart that shows the huge change when I plug the stick in my laptop.

[James Bond 007]

Tried OpenWrt. The ping problem is gone, upload and download throttling is the same.

It seems I'm out of options, this router is just too old and slow so I have to part with it.