Cisco Systems 15327 Configuring POS

CHAPTER
5-1
Ethernet Card Software Feature and Configuration Guide, R7.2
January 2009
5
Configuring POS
This chapter describes advanced packet-over-SONET/SDH (POS) interface configuration for the
ML-Series card. Basic POS interface configuration is included in Chapter 4, “Configuring Interfaces.”
For more information about the Cisco IOS commands used in this chapter, refer to the Cisco IOS
Command Reference publication. POS operation on ONS Ethernet cards, including the ML-Series card,
is described in Chapter 20, “POS on ONS Ethernet Cards.”
This chapter contains the following major sections:
• POS on the ML-Series Card, page 5-1
• Monitoring and Verifying POS, page 5-9
• POS Configuration Examples, page 5-11
POS on the ML-Series Card
Ethernet and IP data packets need to be framed and encapsulated into SONET/SDH frames for transport
across the SONET/SDH network. This framing and encapsulation process is known as POS and is done
in the ML-Series card. Chapter 20, “POS on ONS Ethernet Cards,” explains POS in greater detail.
The ML-Series card takes the standard Ethernet ports on the front of the card and the virtual POS ports
and includes them all as switch ports. Under Cisco IOS, the POS port is an interface similar to the other
Ethernet interfaces on the ML-Series card. It is usually used as a trunk port. Many standard Cisco IOS
features, such as IEEE 802.1 Q VLAN configuration, are configured on the POS interface in the same
manner as on a standard Ethernet interface. Other feat ures and configurations are done strictly on the
POS interface. The configuration of features limited to POS ports is shown in this chapter.
ML-Series SONET and SDH Circuit Sizes
SONET is an American National Standards Institute (ANSI) standard (T1.1051988) for optical digital
transmission at hierarchical rates from 51.840 Mbps (STS-1) to 2.488 Gbps (STS-48) and greater. SDH
is the international standard for optical digital transmission at hierarchical rates from 155.520 Mbps
(STM-1) to 2.488 Gbps (STM-16) and greater.
Both SONET and SDH are based on a structure that has a basic frame and speed. The frame format used
by SONET is the synchronous transport signal (STS), with STS-1 being the base level signal at
51.84 Mbps. A STS-1 frame can be carried in an OC-1 signal. The frame format used by SDH is the
synchronous transport module (STM), with STM-1 being the base level signal at 155.52 Mbps. A STM-1
frame can be carried in an OC-3 signal.