DS1/E1 and DS3 Driver Software. A VxWorks DS1/E1 driver that supports two DS1 interfaces per module and multiple modules was developed for an integrated PBX product. Both telephone and data traffic is supported on the DS1/E1 interfaces and the out-of-band management FDL link is supported, including the transmission and reception of once-per-second statistics messages.
Similar DS1/E1 and DS3 drivers were completed for several other companies, using different processors, hardware architectures and real-time operating systems.
Robbed Bit Signaling Software. A Robbed Bit Signaling (RBS) protocol stack was ported from the host processor to a DSP located on a DS1/E1 interface module. This included the design of a host/DSP communications API (single byte interface) to connect the upper connect/disconnect protocol layers on the host processor with the "bit-banging" per-channel protocol layers on each DSP.
For another customer, a Robbed Bit signaling protocol stack was enhanced to add a number of new European signaling protocols and to expand the controller to handle up to 672 simultaneous voice channels.
SecureId Integration. The RSA SecureId two-factor user authentication software was ported onto an acceess router platform. A number of factors complicated the integration process. While the SecureId software was written for a UNIX streams environment, the router used a round-robin scheduler. And, rather than having one common dialog stack for all users, the SecureId dialog had to be inserted into a separate protocol stack for each user access path.