analogZONE Says . . .

The markets for SONET-based access services including EoS are picking up momentum nicely, thanks in good part to the Virtual Tributary standard and the flexibility and granularity that VT 1.5 services afford. TranSwitch hopes to accelerate this trend with the introduction of a pair of product lines that allow more efficient use of bandwidth thanks to their tributary switching capabilities and an architecture that allows cost-effective upgrades of current equipment to deliver new advanced services.

TranSwitch anticipates that carriers will have to supplement revenues with native services like EoS to supplement flat revenues and make the best use of existing infrastructure. VCAT, LCAS and other efficient protocols will help re-use TDM services that are already "in the ground." But these services require the ability to groom and switch streams at the VT 1.5 level in order to fill frames with whatever content comes in regardless of the time slot that they arrive in.

To meet this demand, TranSwitch's Virtual Tributary Crosspoint (VTXP) devices are intended to add scalable tributary switching and VT 1.5-level grooming capabilities to the ADM in access rings and the MSPP/MSTPs that sit between metro and access rings. As the release above implies, each of the three devices integrates a low-order pointer processor, low-order retimers, a complete set of high-order (TU-3/VC-3) and low-order performance monitors, and a scalable high and low-order non-blocking cross-connect (See Fig. 1).

When integrated into ADMs and Terminal Multiplexers, these devices enable switching of VT1.5 streams anywhere within the SONET connection (and between other VXTP devices) without any additional low-order switch device. This means that a relatively low-cost blade swap will allow a carrier to offer variety of tributary service options.

TranSwitch has also built on this architectural strategy with its PHAST-48 Line Card on a chip. The integrated framer/path terminator integrates a low-order pointer processor and a non-blocking cross-connect that performs both low- and high-order VT switching (See Fig. 2).

The result is what TranSwitch likes to call a "grooming switch", since it can place any VT into any time with VT 1.5 granularity.

This is a significant improvement over the STS-1 resolution offered by most current silicon, a feature that will become increasingly handy as providers offer services that dole out slices of metro ring bandwidth in increasingly finer increments. The PHAST-48's TSI capability complements the multiplexing functionality found in their earlier mapping products. This, and the formidable array of development tools available, should make it easier for designers to create equipment that supports automatic provisioning of GMPLS services a capability that avoids the cumbersome manual reconfiguration of SONET equipment that's currently required. If they deliver as promised, TranSwitch has built a winning product strategy by offering the building blocks to enable easier, more granular delivery of SONET/SDH, EoS, and other frame-based metro services.

Sampling of these products will start in Q3 2004 with production in Q4. The VTXP-6 and VTXP-12 are in 23 mm x 23 mm PBGA-376 and the VTXP-48 is 29 mm x 29 mm SFCBGA-672. The VTXP-6 is priced at $138, the VTXP-12 at $199, and the VTXP-48 at $317 all in volume. The PHAST-48V will be priced at $398.