Rate limit subscriber ASR9k BNG

[prague]

Hi everyone ,

I use the policy map below to limit the subscriber, but when I try to use the whole package or when the speed test is at full load on router, I see packet losses. Anyone know the reason?

policy-map 20M
class class-default
police rate 20 mbps burst 3840000 bytes peak-rate 20 mbps peak-burst 7680000 bytes
conform-action transmit
exceed-action drop
!
!
end-policy-map

Thanks

[Georg Pauwen]

Hello,

post the output of:

show interfaces x

where 'x' is the interface where you applied the service policy.

[prague]

Without policy-map applied on subscriber interface, no packet loss seemed.... but when applied policy and bng configured , problem persists even exceed-action transmit

[Georg Pauwen]

Hello,

it looks like you are policing the default class, which means all traffic that exceeds the policed rate is being dropped. Which traffic (source/destination/port) do you want to police ?

[prague]

Hi,

Limiting pppoe subscriber package . We want to police per pppoe user any any any

[Giuseppe Larosa]

Hello @prague ,

>> We want to police per pppoe user any any any

OK have you applied the QoS policy map using

service-policy out 20M

under the PPP template context ?

Hope to help

Giuseppe

[prague]

We already did basic config, problem is more specific. While the subscriber is using the whole package (all 20mbps), sessions are starting to drop and timeout starts

pppoe bba-group PPPOE
ac name BIGBNG
service selection disable
sessions vlan limit 65535
sessions inner-vlan limit 65535
sessions outer-vlan limit 65535
pado delay 0

interface TenGigE0/0/0/0.100
service-policy type control subscriber PPP
pppoe enable bba-group PPPOE

--------------------

radius attribute

cisco-avpair += ip:sub-qos-policy-out=20M",
cisco-avpair += ip:sub-qos-policy-in=5M"

[prague]

While using all the speed which i specified in police rate , icmp drops starts. Anyone have any other ideas ?

[nethousebimltd]

+1 following

[Aleksandar Vidakovic]

20Mbps on traffic generator my not be exactly 20Mbps on the router because of different encapsulation. You can adjust at using this command:

RP/0/RSP0/CPU0:CORE-TOP(config-subif)#service-policy output Parent account user-defined ?
<-63,+63> Overhead accounting value

Have you tried that already?

/Aleksandar

[prague]

Hi,

Thanks for your answer. But our problem isn't exactly these overheads,

The problem is that the timeout and sessions break when the client router bursts and passes 20 mbps by 1-2 mbps.

[prague]

Line card: A9K-MOD400-SE

MPA : A9K-MPA-20x10G

[Aleksandar Vidakovic]

Let me make sure that I understand the use case. Are you saying that you see PPPoE session flap when the CPE sends traffic that exceeds the configured ingress policer rate?

/Aleksandar

[prague]

Yes, we were trying as pppoe before, but now we are limiting the ip interface police rate to better understand the problem . Here is our config;

interface TenGigE0/0/0/0
service-policy input 20M
service-policy output 20M
vrf INTERNET
ipv4 mtu 1500
ipv4 address XX.XX.XX.XX 255.255.255.252

policy-map 20M
class class-default
police rate 20480000 bps burst 3840000 bytes peak-burst 7680000 bytes
conform-action transmit
exceed-action drop
!
!
end-policy-map

[Georg Pauwen]

Hello,

this thread has become very long, so I am not sure what and what not has already been mentioned, but have you tried to shape instead of policing ? Something like:

policy-map 20M
class class-default
shape average 20480000

?

The thing with policers is that they drop traffic indiscriminately, while shapers are more 'forgiving'...