delay pool not working right?

Hi,

I'm running Squid 2.2.STABLE3(with latest official patches) on Sun
Enterprise 250(Solaris 2.6, 256MB mem), trying to limit outgoing
bandwidth within 256kbps using squid's delay_pools option.

part of squid.conf is:

delay_pools 1
delay_class 1 1
delay_access 1 allow all
delay_parameters 1 32000/32000
delay_initial_bucket_level 50

But, it seems more than 256kbps of outgoing bandwidth is used, up to
300-700kbps, out of about 750kbps capacity. I measured it on my edge
router with 'show interface serial 0' command(yes, it's cisco one).

Is my configuration wrong?

Well, I looked for a documentation about delay_pools on Squid 2.2, but I
couldn't find one. One on Squid FAQ showed it's obsolete for 2.2. If
someone would know where it is written, please let me know.

Thanks.

--
Hiroshi Takata <takata@rsi.co.jp>
Ryoka Systems Inc. Japan