Junos OS Interfaces Command Reference - Juniper Networks

Junos OS 12.1 Interfaces Command Reference
Table 19: Byte Count by PIC Type
PIC Type
Gigabit
Ethernet IQ and
IQE PICs
Non-IQ PIC
IQ and IQE PICs
with a
SONET/SDH
interface
66
Output
Level
Interface
Packet
forwarding
component
Interface
Interface
Packet
forwarding
component
Byte Count Includes
Queued: 490 bytes per packet, representing 478 bytes of
Layer 3 packet + 12 bytes
Transmitted: 490 bytes per packet, representing 478 bytes
of Layer 3 packet + 12 bytes
RED dropped: 496 bytes per packet representing 478 bytes
of Layer 3 packet + 18 bytes
Queued: 478 bytes per packet, representing 478 bytes of
Layer 3 packet
Transmitted: 478 bytes per packet, representing 478 bytes
of Layer 3 packet
For Juniper Networks T Series, TX Series, T1600, and MX
Series routers:
Queued: 478 bytes of Layer 3 packet.
Transmitted: 478 bytes of Layer 3 packet.
For Juniper Networks T4000 routers with Type 5 FPCs:
Queued: 478 bytes of Layer 3 packet + the full Layer 2
overhead including 4 bytes CRC + the full Layer 1 overhead
8 bytes preamble + 12 bytes Inter frame Gap.
Transmitted: 478 bytes of Layer 3 packet + the full Layer
2 overhead including 4 bytes CRC + the full Layer 1 overhead
8 bytes preamble + 12 bytes Interframe Gap.
For Juniper Networks M Series routers:
Queued: 478 bytes of Layer 3 packet.
Transmitted: 478 bytes of Layer 3 packet + the full Layer
2 overhead.
Queued: 482 bytes per packet, representing 478 bytes of
Layer 3 packet + 4 bytes
Transmitted: 482 bytes per packet, representing 478 bytes
of Layer 3 packet + 4 bytes
RED dropped: 482 bytes per packet, representing 478 bytes
of Layer 3 packet + 4 bytes
Queued: 478 bytes per packet, representing 478 bytes of
Layer 3 packet
Transmitted: 486 bytes per packet, representing 478 bytes
of Layer 3 packet + 8 bytes
Comments
The 12 additional bytes include
6 bytes for the destination MAC
address + 4 bytes for the VLAN
+ 2 bytes for the Ethernet type.
For RED dropped, 6 bytes are
added for the source MAC
address.
–
The Layer 2 overhead is 14
bytes for non-VLAN traffic and
18 bytes for VLAN traffic.
The additional 4 bytes are for
the Layer 2 Point-to-Point
Protocol (PPP) header.
For transmitted packets, the
additional 8 bytes includes 4
bytes for the PPP header and
4 bytes for a cookie.
Copyright © 2012, Juniper Networks, Inc.