The Metro Ethernet Forum (MEF) Carrier Ethernet (CE)
2.0 set of standards has stringent requirements to the bandwidth profile
enforcement at the user-to-network interfaces (UNI). MEF CE 2.0 certification
compliance allows only a 2 percent deviation from UNI committed or
peak rate across all frame sizes. This means that the policers should
take into account the frame size at the UNI interface, including frame
checksum and excluding all additional overheads that might be added
inside the service provider network (such as S-VLANs).
In order to address the MEF CE 2.0 stringent requirements to
the bandwidth profile, policer-overhead adjustment is defined
on a per IFL or direction granularity. The policer-overhead adjustment is in the range of -16 bytes to +16 bytes and is applied
for all the policers that take into account Layer 1/ Layer 2 (L1/L2)
packet length in the specified IFL or direction, including corresponding
logical interface family (IFF) feature policers.
To configure the policer-overhead:
- At the [edit interfaces] hierarchy level in configuration
mode, create the interface on which to add the policer-overhead to
input or output traffic.
[edit interfaces]
user@host# edit interfaces interface name
For example:
[edit interfaces interface name]
user@host# edit xe-0/1/6
- Create the unit on which to add the policer overhead.
[edit interfaces unit]
[edit interfaces interface name unit unit-number]
For example:
[edit interfaces unit]
user@host# edit xe-0/1/6 unit 0
- Configure the policer-overhead for the ingress policer.
[edit interfaces interface name unit unit-number ]
user@host# set policer-overhead ingress value in bytes (-16..+16 bytes)
For example:
[edit xe-0/1/6 unit 0]
user@host# set policer-overhead ingress 10;
- Configure the policer-overhead for the egress policer.
user@host# set policer-overhead egress value in bytes (-16..+16 bytes)
[edit xe-0/1/6 unit 0]
user@host# set policer-overhead egress 10;
- Verify the configuration.
[edit interfaces]
user@host# show interfaces xe-0/1/6
xe-0/1/6 {
unit 0 {
policer-overhead {
ingress 10;
egress 10;
}
}
}
user@host>show interfaces xe-0/1/6
Physical interface: xe-0/1/6, Enabled, Physical link is Up
Interface index: 161, SNMP ifIndex: 544
Link-level type: Ethernet, MTU: 1514, MRU: 1522, LAN-PHY mode, Speed: 10Gbps, BPDU Error: None, MAC-REWRITE Error: None,
Loopback: None, Source filtering: Disabled, Flow control: Enabled
Pad to minimum frame size: Disabled
Device flags : Present Running
Interface flags: SNMP-Traps Internal: 0x4000
Link flags : None
CoS queues : 8 supported, 8 maximum usable queues
Schedulers : 0
Current address: 00:23:9c:fc:a8:58, Hardware address: 00:23:9c:fc:a8:58
Last flapped : 2015-09-13 20:12:36 PDT (14:21:57 ago)
Input rate : 0 bps (0 pps)
Output rate : 0 bps (0 pps)
Active alarms : None
Active defects : None
PCS statistics Seconds
Bit errors 0
Errored blocks 0
Link Degrade :
Link Monitoring : Disable
Interface transmit statistics: Disabled
Logical interface xe-0/1/6.0 (Index 339) (SNMP ifIndex 571)
Flags: Up SNMP-Traps 0x4004000 Encapsulation: ENET2
Policer overhead :
Ingress policer overhead : 10 bytes
Egress policer overhead : 10 bytes
Input packets : 0
Output packets: 0
Protocol multiservice, MTU: Unlimited
Flags: Is-Primary
user@host> show interfaces xe-0/1/6.0
Logical interface xe-0/1/6.0 (Index 339) (SNMP ifIndex 571)
Flags: Up SNMP-Traps 0x4004000 Encapsulation: ENET2
Policer overhead :
Ingress policer overhead : 10 bytes
Egress policer overhead : 10 bytes
Input packets : 0
Output packets: 0
Protocol multiservice, MTU: Unlimited
Flags: Is-Primary
