STM-4 - Applications

VCL100 STM-1/4 Applications

STM-1/4 Add-Drop Multiplexer

The ADM configuration can be achieved using 1/2xSTM-1 card or 1xSTM-4 card, 1 Cross-connect card, 1 MIC, 1 PSS1, 1 PSU1 and a suitable combination of E1 / E3 / E4 / DS1 / DS3 / Ethernet tributary cards. In case STM-1 aggregate card redundancy is required, a second aggregate card can be used. For cross-connect card redundancy, a second cross-connect card can be used. Power supply redundancy can also be provided, by using a second power supply card.

STM-1/4 Terminal Multiplexer

This TMUX configuration can be achieved with 1xSTM-1 card or 1xSTM-4 card , 1 cross-connect card, 1 MIC, 1 PSS1, 1 PSU1 and a suitable combination of E1 / E3 / E4/ DS1 / DS3 / Ethernet tributary cards. For applications that do not require cross-connect capability, a cross-connect bypass card can be used in the cross-connect slot. Redundancy can be provided for processor card, aggregate card, cross connect card and power supply card.

STM-1/4 Stand-alone Cross Connects

In order to connect a VCL100 STM-1/4 based ring to the backbone a minimum of 3 interfaces are required on the node. For such applications, a cross connect configuration is supported on VCL100 STM-1/4. A 4x4 STM-1 or STM-4 cross-connect can be created using appropriate cards and slots in VCL100 STM-1/4.

For 4x4 STM-1 (252x252 E1s) cross-connect, 2 2xSTM-1 cards and one STM-1cross-connect card can be used to create the cross-connect.

For 4x4 STM-4 (1008x1008 E1s) cross-connect, 4 1xSTM-4 cards and one STM-4 cross connect card using 2 aggregate slots and 2 tributary slots.

Both the configurations will additionally need 1 PSS card, 1 PSU card and 1 MIC.

STM-1/4 Regenerator

VCL100 STM-1/4 can be configured as a regenerator for all STM-1/4 interfaces. This can be achieved by having 1 aggregate card, 1 PSS1, 1 MIC and 1 PSU1 in the system. The receive clock shall be used in the transmit direction. Hence a separate card for supply timing will not be required.

Network Applications

STM-4 Rings

VCL100 STM-1/4 is fully compatible with other member of the VCL100 STM-1/ STM-4 family. It can therefore be seamlessly used in an end-to-end network configuration from the customer premises to the optical core.

The following figure shows a STM-4 network built using VCL100 STM-1/STM-4 with low drop requirements at a couple of locations. These requirements can be cost-effectively addressed by using a VCL100 STM-1/4.

STM-1/4 Subtended Rings

The STM-1 tributary modules of VCL100 STM-1/4 can act as SDH NEs completing the Subtended Rings, or LTE performing Line, Span or Ring Switching as well as pass DCC. The modules are able to insert/drop traffic through the switching matrix to any of the other tributary/aggregate cards. It is possible to connect a mix of STM-1/4 rings through the VCL100 (STM-1 / STM-4).

Transparent LAN service

The VCL100 STM-1/4 ETC card is transparent to all higher layer protocols and provides point-topoint connections between remote Ethernet segments. The ETC is well suited for LAN interconnection services among geographically dispersed corporate offices. Typical LAN interconnection solutions use expensive ATM interfaces on routers to connect to SDH multiplexers. But the 10/100 Base-T interfaces on the VCL100 STM-1/4 SDH node provide a much more cost-effective solution.

Conventional Solution using ATM interfaces on Routers

Consider connecting 8 subscribers requesting bandwidth of 6 Mbps each. Each router need 8 E3 interfaces for transporting this traffic and this necessitates an STM-4 Backbone.

VCL100 STM-1/4 ETC Solution

In the VCL100 STM-1/4 based solution the traffic from each of these Ethernet connections can be collected using a 10/100Base-T interface on the routers and SDH nodes. The VCL100 STM-1/4 SDH node requires an 8x10/100Base-T ETC card and the traffic from these 8 different connections is flexibly mapped, requiring only an STM-1 Backbone. In addition, upgrading from the existing bandwidth is software-selectable resulting in cost savings in terms of interface cards and operational expenses.

Integrated Voice and Data Network

In a typical Interconnect Service voice and data traffic from multiple corporate offices need to be interconnected in a cost effective manner. A conventional solution uses separate voice and data networks to carry this traffic over separate fibers. Using the VCL100 STM-1/4, which provides both TDM and Ethernet interfaces through the ETC, a service provider can carry both voice and data over the same fiber pair using the same equipment.

Example: There is a need to provide data connectivity of 10 Mbps between two locations. There is also a voice traffic requirement of 21E1s between the same two locations. Consider two different distances between the two locations: 10 km and 50km

Conventional Ethernet + SDH solution

In this scenario, data and voice are carried over different fiber pairs using Gigabit Ethernet (GigE) for data and conventional SDH for voice (Figure 1). GigE LX/HX solution can drive only up to 10 km. GigE ZX solution can provide 70 km spans but is expensive.

VCL100 STM-1/4 ETC solution

In this solution, data and voice are carried over the same fiber pair by mapping the 10/100Base-T Ethernet traffic onto SDH. The network is a linear STM-4 network, which can be optionally configured for 1+1 protection. Longer distances can be achieved by using long haul lasers that are relatively much more cost-effective.