When you enable mpd5 on Freebsd 9.1, the outgoing speed of the Internet connection on the VPN clients and server drops. Where to dig?

Question

FreeBSD

Set up Freebsd 9.1 vpn server on mpd5 (Version 5.6). There was a VPN server, everything was in order. The server was updated a very long time ago, because. performs only three functions, and there was no need to update. Recently I noticed a very fast drop in the speed of the Internet connection, with mpd5 enabled, both on the server and on clients that are connected via VPN. Turning off MPD5 - all the fire. Has anyone encountered a similar problem? Changed network cards to new ones - no result.
mpd.conf
#
# MPD configuration file
#
# This file defines the configuration for mpd: what the
# bundles are, what the links are in those bundles, how
# the interface should be configured, various PPP parameters,
#etc. It contains commands just as you would type them
# in at the console. Lines without padding are labels. Lines
# starting with a "#" are comments.
#
# $Id: mpd.conf.sample,v 1.46 2009/04/29 11:04:17 amotin Exp $
#
####################### ##########################################
startup:
# ▒▒▒▒▒ ▒ ▒▒▒▒▒▒ ▒▒▒ ▒▒▒▒▒▒▒ ▒ web - intarface
# set user password cancer # configure the console set console self 127.0.0.1 5005 set console open # configure the web server set web self 0.0.0.0 5006 set web open
default:
load pptp_server
pptp_server:
#
▒▒▒▒▒▒▒▒ VPN ▒.
set ippool add pool1 192.168.100.50 192.168.100.99
# Create clonable bundle template named B
create bundle template B
set iface enable proxy-arp
set iface idle 0
set iface enable tcpmssfix
set ipcp yes vjcomp
# Specify IP address pool for dynamic assigment.
set ipcp ranges 192.168.100.1/32 ippool pool1
set ipcp dns 192.168.0.14
# The five lines below enable Microsoft Point-to-Point encryption
# (MPPE) using the ng_mppc(8) netgraph node type.
set bundle enable compression
set ccp yes mppc
set mppc yes e40
set mppc yes e128
set mppc yes stateless
# Create clonable link template named L
create link template L pptp
# Set bundle template to use
set link action bundle B
# Multilink adds some overhead, but gives full 1500 MTU.
set link enable multilink
set link yes acfcomp protocomp
set link no pap chap eap
set link enable chap
set link keep-alive 10 60
# We reducing link mtu to avoid GRE packet fragmentation
set link mtu 1456
# Configure PPTP
▒▒▒▒▒▒▒
IP .х.х.х
# set pptp self 10.0.0.2
# Allow to accept calls
set link enable incoming
Tell me, where can I dig? Google has been working for a month, nothing sensible and specific on this problem was found.
Additional information is required - I will send it without problems.

Answer 1

Few initial data. Do clients go to the Internet through the same VPN server when connected?

Answer 2

Yes, clients use Internet VPN servers. There are essentially two clients, more is not required. What other data are you interested in?