Multiple applications
Potential applications for the 1850 TSS-3 include:
•Ethernet demarcation
•Ethernet service aggregation
•Ethernet over PDH (EoPDH)
•Ethernet extension
In Figure 1, the 1850 TSS-3 is in the Ethernet- demarcation role, with the demarcation point shown as a dotted line, representing the point where traffic crosses from the customer-owned
Figure 1. Ethernet demarcation
equipment to the service-provider-owned cus- tomer premises equipment (CPE). At the demar- cation point, the 1850 TSS-3 accepts the traffic stream on the customer side and transports this traffic to one or more network elements in a carrier Ethernet network. This applica- tion offers fault diagnostics and monitoring, traffic rate limiting and virtual LAN (VLAN) stacking (capability of offering multiple, discrete VLANs over a single connection).
1850
TSS-3
Demarcation
Carrier Ethernet
Network
(Ethernet or MSPP
or WDM-based)
WDM – Wavelength Division Multiplexing MSPP – Multiservice Provisioning Platform
1850 TSS-3
Demarcation 
In Figure 2, the 1850 TSS-3 is in an Ethernet service-aggregation configuration, in this case acting as a carrier-class Ethernet switch, accepting multiple inputs from the customer side and aggregat- ing them for onward transmission on the network side. Network-side redundancy can be provided by Rapid Spanning Tree Protocol or Ethernet dual homing, two methods for providing automatic backup paths.
Figure 2. Ethernet service aggregation
1850 TSS-3 | Metro Ethernet | 1850 TSS-3 |
| Network | |
(Ethernet or MSPP or CWDM-based)
DemarcationDemarcation
CWDM – Coarse Wavelength Division Multiplexing
4Alcatel-Lucent 1850 TSS-3 Transport Service Switch
