Frustrating network latency issue on NetBSD 6.1

[Mayuresh <mayuresh%acm.org@localhost>]

I am having some terrible network latency issues with NetBSD 6.1 i386,
since my last hardware upgrade. Sadly, both the laptop and router are new
so not able to figure out what contributes to the issue.

One observation is, on the same setup, if I boot to Linux I do not find
the latency issue at all.

What I call latency issue basically appears when I connect to a remote (or
even on my home network) machine over ssh, typing is very jerky. A lot of
characters appear together in bunches after a few seconds of typing them.
It's getting unbearably frustrating.

Would appreciate help in understanding and resolving the issue.

lspci shows the wifi adapter as:
02:00.0 Network controller: Intel Corporation Centrino Advanced-N 6205
(rev 34)

It is configured as iwn0.

WPA2-PSK encryption is used as only that is supported on the router that
runs DD-WRT firmware.

(Ok, an obvious thing I'll try is by disabling encryption for a while.)

Mayuresh