, or the aggregation of two B channels into one 112/128 Kbps channel. The problem with ISDN was, and still is, availability. Although almost all telephone companies offer some form of high-bandwidth digital transmission service to business and residential consumers, not all offer ISDN. Intel can take much the credit for a surge in ISDN deployment by the Regional Bell Operating Companies (RBOC) and GTE; they worked cooperatively with them to demonstrate that customers wanted broadband connectivity (at a time when DSL and cable modems were little known or nonexistent). Remote access to enterprise network services and telecommuting (replacing the physical commute with a virtual one) led to many ISDN installations. Besides complaining that ProShare required network services that were not always available, Intel's competitors also criticized the company for not embracing the standard that the International Telecommunications Union's Telecommunications Standardization Sector (CCITT/ITU-T) ratified in 1990. Without support for standards, ProShare could not interoperate with other systems. Intel's response was rational: the standard in question, known as H.320, was overkill for the desktop, and too expensive to implement. Intel had managed to keep the ProShare Video System 200 priced at less than $1,500 for most installations, and less as time progressed. H.320 required expensive hardware codecs, but ProShare compressed with inexpensive software-only codecs. Intel eventually implemented the mandatory portions of the standard, but only after making their point. The desktop video communication market, and personal conferencing, would not happen until the ITU-T ratified a desktop standard. That standard also represented the demise of ProShare. In 1996, the new personal conferencing standard, H.324, emerged. Its target was video communication over POTS. Even before H.324, another standard, aimed only at graphics conferencing, was ratified by the ITU-T. The formal name for this standard is Transmission Protocols for Multimedi