Cisco Systems 15327 Framing Mode, Encapsulation, and CRC Support

5-4
Ethernet Card Software Feature and Configuration Guide, R7.2
January 2009
Chapter 5 Configuring POS
Framing Mode, Encapsulation, and CRC Support
Framing Mode, Encapsulation, and CRC Support
The ML-Series cards on the ONS 15454 and ONS 15454 SDH supp ort two modes of the POS framing
mechanism, GFP-F framing and HDLC framing (default). The framing mode, encapsulation, and CRC
size on source and destination POS ports must match for a POS circuit to function prope rly. Chapter 20,
“POS on ONS Ethernet Cards,” explains the framing mechanisms, encapsulations, and cyclic
redundancy check (CRC) bit sizes in detail.
Supported encapsulation and CRC sizes for the framing types are detailed in Table 5-3.
Note ML-Series card POS interfaces normally send PDI-P to the far-end when the POS link goes down or RPR
wraps. ML-Series card POS interfaces do not send PDI-P to the far-end when PDI-P is detected, when
RDI-P is being sent to the far-end or when the only defects detected are GFP LFD, GFP CSF, VCAT
LOM or VCAT SQM.
Configuring POS Interface Framing Mode
You configure framing mode on an ML-Series card only through CTC. For more information on
configuring framing mode in CTC, see Chapter 2, “CTC Operations .”
Configuring POS Interface Encapsulation Type
The default Cisco EoS LEX is the primary encapsulation of ONS Ethernet cards. This encapsulation is
used under HDLC framing with the protocol field set to the values specified in Internet Engineering Task
Force (IETF) Request For Comments (RFC) 1841. Under GFP-F framing, the Cisco IOS CLI also uses
the keyword lex. With GFP-F framing, the lex keyword is used to represent standard mapped Ethernet
over GFP-F according to ITU-T G.7041.
To configure the encapsulation type for a ML-Series card, perform the following step s beginning in
global configuration mode:
Table 5-3 Supported Encapsulation, Framing, and CRC Sizes for ML-Series Cards on the
ONS 15454 and ONS 15454 SDH
Encapsulations for
HDLC Framing CRC Sizes for HDLC Framing Encapsulations for GFP-F Framing CRC Sizes for GFP-F Framing
ML-Series LEX (default)
Cisco HDLC
PPP/BCP
16-bit
32-bit (default)
LEX (default)
Cisco HDLC
PPP/BCP
32-bit (default)
Command Purpose
Step 1 Router(config)# interface pos
number
Activates interface configuration mode to
configure the POS interface.
Step 2 Router(config-if)# shutdown Manually shuts down the interface. Encapsulation
changes on POS ports are allowed only when the
interface is shut down (ADMIN_DOWN).