problem with pppoe and vpn data receive

hello
i have a mikrotik routerboard 450g
by this configuration for banthwidth control for pppoe and vpn connection
when pppoe user or vpn user connect their connection after a random time between 1 min to 15 min internet receive stop without pppoe or vpn connection disconnect and after 30 sec to 1 min receive again start automatically
but when users connect without any radius authentication (by dhcp) users has no any problem in receive data from internet
additional we use a radius authentication server for user accounting and users get ip from radius server , all ip addresses use nat in mikrotik
any body can help me to find this problem solution
thanks

configurTION

PCQ setting (queue type)

[admin@MikroTik] /queue type> print 
 5 name="PCQ_64_down" kind=pcq pcq-rate=64000 pcq-limit=50 pcq-classifier=dst-address pcq-total-limit=2000
 6 name="PCQ_64_up" kind=pcq pcq-rate=64000 pcq-limit=50 pcq-classifier=src-address pcq-total-limit=2000 
 7 name="PCQ_128_down" kind=pcq pcq-rate=128000 pcq-limit=50 pcq-classifier=dst-address    pcq-total-limit=2000 
 8 name="PCQ_128_up" kind=pcq pcq-rate=128000 pcq-limit=50 pcq-classifier=src-address pcq-total-limit=2000 
 9 name="PCQ_256_down" kind=pcq pcq-rate=256000 pcq-limit=50 pcq-classifier=dst-address    pcq-total-limit=2000 
10 name="PCQ_256_UP" kind=pcq pcq-rate=256000 pcq-limit=50 pcq-classifier=src-address pcq-total-limit=2000 
11 name="PCQ_512_DOWN" kind=pcq pcq-rate=512000 pcq-limit=50 pcq-classifier=dst-address   pcq-total-limit=2000 
12 name="PCQ_512_UP" kind=pcq pcq-rate=512000 pcq-limit=50 pcq-classifier=src-address pcq-total-limit=2000 
13 name="PCQ_1M_DOWN" kind=pcq pcq-rate=1024000 pcq-limit=50 pcq-classifier=dst-address   pcq-total-limit=2000 
14 name="PCQ_1M_UP" kind=pcq pcq-rate=1024000 pcq-limit=50 pcq-classifier=src-address pcq-total-limit=2000

queue tree

[admin@MikroTik] /queue tree> print 
Flags: X - disabled, I - invalid 
 0   name="64_download" parent=global-out packet-mark="" limit-at=0 queue=default priority=1 max-limit=0 burst-limit=>
     burst-threshold=0 burst-time=0s 
 1   name="download" parent=64_download packet-mark=PM_64 limit-at=0 queue=PCQ_64_down priority=8 max-limit=0 
     burst-limit=0 burst-threshold=0 burst-time=0s 
 2   name="64_UPLOAD" parent=global-out packet-mark="" limit-at=0 queue=default priority=1 max-limit=0 burst-limit=0 
     burst-threshold=0 burst-time=0s 
 3   name="upload_64" parent=64_UPLOAD packet-mark=PM_64 limit-at=0 queue=PCQ_64_up priority=8 max-limit=0 
     burst-limit=0 burst-threshold=0 burst-time=0s 
 4   name="128_download" parent=global-out packet-mark="" limit-at=0 queue=default priority=1 max-limit=0 
     burst-limit=0 burst-threshold=0 burst-time=0s 
 5   name="download_128" parent=128_download packet-mark=PM_128 limit-at=0 queue=PCQ_128_down priority=8 max-limit=0 
     burst-limit=0 burst-threshold=0 burst-time=0s 
 6   name="128_upload" parent=global-out packet-mark="" limit-at=0 queue=default priority=1 max-limit=0 burst-limit=0 
     burst-threshold=0 burst-time=0s 
 7   name="upload128" parent=128_upload packet-mark=PM_128 limit-at=0 queue=PCQ_128_up priority=8 max-limit=0 
     burst-limit=0 burst-threshold=0 burst-time=0s 
 8   name="256_download" parent=global-out packet-mark="" limit-at=0 queue=default priority=1 max-limit=0 
     burst-limit=0 burst-threshold=0 burst-time=0s
9   name="download256" parent=256_download packet-mark=PM_256 limit-at=0 queue=PCQ_256_down priority=8 max-limit=0 
     burst-limit=0 burst-threshold=0 burst-time=0s 
10   name="256_upload" parent=global-out packet-mark="" limit-at=0 queue=default priority=1 max-limit=0 burst-limit=0 
     burst-threshold=0 burst-time=0s 
11   name="upload256" parent=256_upload packet-mark=PM_256 limit-at=0 queue=PCQ_256_UP priority=8 max-limit=0 
     burst-limit=0 burst-threshold=0 burst-time=0s 
12   name="512_download" parent=global-out packet-mark="" limit-at=0 queue=default priority=1 max-limit=0 
     burst-limit=0 burst-threshold=0 burst-time=0s 
13   name="download512" parent=512_download packet-mark=PM_512 limit-at=0 queue=PCQ_512_DOWN priority=8 max-limit=0 
     burst-limit=0 burst-threshold=0 burst-time=0s 
14   name="512_upload" parent=global-out packet-mark="" limit-at=0 queue=default priority=1 max-limit=0 burst-limit=0 
     burst-threshold=0 burst-time=0s 
15   name="upload512" parent=512_upload packet-mark=PM_512 limit-at=0 queue=PCQ_512_UP priority=8 max-limit=0 
     burst-limit=0 burst-threshold=0 burst-time=0s 
16   name="1M_download" parent=global-out packet-mark="" limit-at=0 queue=default priority=1 max-limit=0 burst-limit=>
     burst-threshold=0 burst-time=0s 
17   name="download1M" parent=1M_download packet-mark=PM_1024 limit-at=0 queue=PCQ_1M_DOWN priority=8 max-limit=0 
     burst-limit=0 burst-threshold=0 burst-time=0s 
18   name="1M_upload" parent=global-out packet-mark="" limit-at=0 queue=default priority=8 max-limit=0 burst-limit=0 
     burst-threshold=0 burst-time=0s 
19   name="upload1M" parent=1M_upload packet-mark=PM_1024 limit-at=0 queue=PCQ_1M_UP priority=8 max-limit=0 
     burst-limit=0 burst-threshold=0 burst-time=0s

mangle

[admin@MikroTik] /ip firewall mangle> print 
Flags: X - disabled, I - invalid, D - dynamic 
 0   ;;; Con & packet mark 64
     chain=forward action=mark-connection new-connection-mark=CM_64 passthrough=yes src-address-list=Nat_PtmP_64 
 1   chain=forward action=mark-packet new-packet-mark=PM_64 passthrough=yes src-address-list=Nat_PtmP_128 
     connection-mark=CM_64 
 2   ;;; Con & packet mark 128
     chain=forward action=mark-connection new-connection-mark=CM_128 passthrough=yes src-address-list=Nat_PtmP_128 
 3   chain=forward action=mark-packet new-packet-mark=PM_128 passthrough=yes connection-mark=CM_128 
 4   ;;; Con & packet mark 256
     chain=forward action=mark-connection new-connection-mark=CM_256 passthrough=yes src-address-list=Nat_PtmP_256 
 5   chain=forward action=mark-packet new-packet-mark=PM_256 passthrough=yes connection-mark=CM_256 
 6   ;;; Con & packet mark 512
     chain=forward action=mark-connection new-connection-mark=CM_512 passthrough=yes src-address-list=Nat_PtmP_512 
 7   chain=forward action=mark-packet new-packet-mark=PM_512 passthrough=yes src-address-list=Nat_PtmP_512 
     connection-mark=CM_512 
 8   ;;; Con & packet mark 1024
     chain=forward action=mark-connection new-connection-mark=CM_1024 passthrough=yes src-address-list=Nat_PtmP_1024 
 9   chain=forward action=mark-packet new-packet-mark=PM_1024 passthrough=yes src-address-list=Nat_PtmP_1024 
     connection-mark=CM_1024

ip firewall nat settings

[admin@MikroTik] /ip firewall nat> print 
Flags: X - disabled, I - invalid, D - dynamic 
 0   ;;; PPPOE 64k
     chain=srcnat action=src-nat to-addresses=X.X.X.X (public IP) to-ports=0-65535 
     src-address-list=Nat_PtmP_64 

 1   ;;; PPPOE 128k
     chain=srcnat action=src-nat to-addresses=X.X.X.X to-ports=0-65535 
     src-address-list=Nat_PtmP_128 

 2   ;;; PPPOE 256k
     chain=srcnat action=src-nat to-addresses=X.X.X.X to-ports=0-65535 
     src-address-list=Nat_PtmP_256 

 3   ;;; PPPOE 512k
     chain=srcnat action=src-nat to-addresses=X.X.X.X to-ports=0-65535 
     src-address-list=Nat_PtmP_512 

 4   ;;; PPPOE 1024k
     chain=srcnat action=src-nat to-addresses=X.X.X.X to-ports=0-65535 
     src-address-list=Nat_PtmP_1024

address lists

[admin@MikroTik] /ip firewall address-list> print 
Flags: X - disabled, D - dynamic 
 #   LIST                                                                   ADDRESS                        
 0   Nat_PtmP_128                                                           172.5.8.0/24                   
 1   Nat_PtmP_256                                                           172.5.9.0/24                   
 2   Nat_PtmP_512                                                           172.5.10.0/24                  
 3   Nat_PtmP_1024                                                          172.5.11.0/24                  
 4   Nat_PtmP_64                                                            172.5.7.0/24

please help me friends :frowning:

Dear Forever.
I have the exact problem as you. Did you find any solution up to now? or any changes which make some improvments for vpn user.
Although my problem is somewhat different, in fact my users face with about 3 secound interruption during browsing oor downloading.

Thanks in advance

Also I have Squid cache server on slackware. I am doubt in cache or queueing mechanism on it or in mikrotik.
Please Guide me or at least a comment to negotiate!?

Thanks