Cyan Z-Series Engineering and Planning Guide Release 5.0
700-0023-05-00 Rev. 1 © 2013 Cyan, Inc. Proprietary Information Page 211
MST Multiple Spanning Tree
MSTI Multiple Spanning Tree Instance
MSTP
Multiple Spanning Tree Protocol — As defined in IEEE 802.1Q, provides simple and full
connectivity for frames assigned to any given VLAN throughout a bridged LAN comprising
arbitrarily interconnected bridges, each operating MSTP, STP, or RSTP. MSTP allows frames
assigned to different VLANs to follow separate paths, each based on an independent Multiple
Spanning Tree Instance (MSTI), within Multiple Spanning Tree (MST) Regions composed of
LANs and or MST Bridges. These Regions and the other Bridges and LANs are connected into
a single Common Spanning Tree (CST).
MTNM Multi-Technology Network Management
MTU Maximum Transmission Unit
Multiplex Combining multiple signals for simultaneous transmission across a single physical channel.
Muxponder Multiplexed transponder
NE Network Element
NEBS Network Equipment Building Systems
NMS Network Management Station
– or –
Network Management System
NNI Network-to-Network Interface
NTP Network Time Protocol
OADM Optical Add/Drop Multiplexer
OAM Operation, Administration and Maintenance
OAMPDU
OAM Protocol Data Units are link-layer OAM messages transmitted in untagged slow protocol
frames. Per IEEE 802.3ah, OAMPDUs are normal Ethernet frames that use a specific multicast
destination address and EtherType. OAMPDUs contain control and status information needed
to monitor and troubleshoot OAM-enabled links.
OCh Optical Channel
ODU Optical Data Unit -
OEO Optical-Electrical-Optical
OMS Optical Multiplex Section
OOO Optical-Optical-Optical
OOS Out of Service
OPS
Optical Protection Switch — The Cyan Optical Protection Switch (OPS) uses low-
technology to provide protection against fiber cuts and failures. It provides redundant path
protection for telecommunication transmission systems. The OPS operates independent of rate,
format, and wavelength.
The OPS provides 1+1 protection. It continuously monitors optical power on both its primary and
secondary links. If received optical power on the active link drops below a configured threshold,
the OPS switches the optical signal to the standby link within 25 ms.
OSC
Optical Supervisory Channel — In order to supervise all network elements in the network,
without relying on an external DCN, the Cyan systems provide an Optical Supervisory Channel
(OSC). Each Cyan Z-Series shelf connects to its neighbors via a 100 Mbps Ethernet channel
carried in-band over the optical network.
The system provides an embedded OSC that is resident in each Cyan network element. These
select Cyan optical interfaces insert a 100 Mbps OSC on 1510nm and provide transparent links
between each Cyan NE in the network. The OSC is a separate channel that carries overhead
information for network management purposes that is added and dropped at each network
element. It does not affect traffic.
To Next Page