Q: What is V.90?
A: V.90 technology allows dial-up modems to receive data at up to 53 Kbps over the standard public switched telephone network. Actul V.90 modem connections will be between 33.6 Kbps and 53 Kbps depending on modem and line conditions.

Q: Why is V.90 important?
A: While DSL service is growing quickly, it represents only a small percentage of the overall Internet connections. As of the first quarter of calendar year 2000, there were over 42 million subscribers using dial-up service to access the Internet.

Q: If my computer has a V.90 modem, why do I often get connections of 28.8 Kbps or less?
A: There are several reasons why a V.90 modem will not perform up to its potential. First, the inherent characteristics of copper wire will not support the transmission of analog V.90 data speeds as the length of the copper wire grows. As a result, the same users that are too far from the central office to get DSL also can not get V.90 on their dial-up modems. Secondly, digital pair gain systems like DAMLs and older DLCs can not support V.90 transmission speeds. There are also many additional impairments that decrease the performance of V.90 modems such as modem incompatibility, load coils, and noisy loops.

Q: Why did CTDI/GoDigital develop V.90 transmission capability?
A: CTDI/GoDigital wanted to help local exchange carriers improve the quality of service provided to their customers by increasing dial-up modem speeds. The rapid growth in dial-up Internet access is a key driver of second line growth. CTDI/GoDigital’s products now allow local exchange carriers to meet the demand for multiple access line with V.90 quality.

Q: What V.90 modem transmission problems does CTDI/GoDigital solve?
A: CTDI/GoDigital’s V.90 capability solves two key transmission problems. First, CTDI/GoDigital eliminates the distance problem associated with analog V.90 transmission. By converting the analog data stream to digital transmission, CTDI/GoDigital can transport V.90 speeds to virtually any location on the network. Second, CTDI/GoDigital enables V.90 speeds over the highly preferred TR-57 analog switch interface. CTDI/GoDigital is the only digital pair gain vendor capable of supporting V.90 speeds on all channels at a compelling cost using a non-integrated interface.

Q: How does a CTDI/GoDigital system support V.90?
A: CTDI/GoDigital spent over a year developing a highly sophisticated digital signal processing (DSP) approach to supporting V.90 through its GDSL systems. The DSP code base individually manages modem connections on each system channel to provide for broad client and server modem compatibility. Patented features like Automatic Pad Detection compensate for central office switch characteristics that can impact V.90 performance.

Q: Does the new GDSL XCel-8 V.90 line card work with my existing CTDI/GoDigital outside plant equipment?
A: Yes. The DSP approach has allowed CTDI/GoDigital to provide V.90 capability through a DSP chip on the line card. All outside plant elements are the same for the GDSL XCel-8 and the GDSL-8.

Q: What is CTDI/GoDigital charging for V.90 capability?
A: CTDI/GoDigital is not charging a price premium for V.90. V.90 is a standard feature of CTDI/GoDigital GDSL voice systems.

Q: How many concurrent V.90 connections can CTDI/GoDigital support?
A: The GDSL XCel-8 supports concurrent V.90 connections on all eight system channels.

Q: Is the GDSL XCel-8 with V.90 capability generally available?
A: Yes. The GDSL XCel-8 can be ordered today from CTDI/GoDigital or through authorized distributors such as GTE Supply, Alltel Supply, and Dakota Supply Group.