RSS
  Eicon DIVA Pro 2.0 Hits All The Righ t ISDN Notes By David Willis DIVA Pro 2.0 from Eicon Technology Corp. delivers almost everything you could ask for in a single-user ISDN device. This internal communications adapter is available in both ISA and Peripheral Component Interconnect (PCI) flavors and runs over Microsoft Corp.'s Windows95, Windows 3.1 and Windows NT and IBM Corp.'s OS/2 operating systems. Like most internal devices, DIVA Pro 2.0 is faster than external adapters, which are hampered by serial port bottlenecks. The DIVA Pro adapter is also easier to set up than most ISDN routers, and usage monitoring is easier as well. In fact, DIVA Pro is one of the easiest ISDN devices of any type to set up. The DIVA Pro 2.0 is a single physical card, yet it offers users a variety of logical modems on-board. First and f oremost, it's an ISDN adapter that supports 64-Kbps or 128-Kbps connections (or slower, if your ISDN service requires it). Under Windows95, it uses Dial-Up Networking to establish connections to remote networks. An on-board modem lets you connect to analog lines over your ISDN connection. You can't plug the card into a plain old telephone service (POTS) line, but you can connect to remote analog modems using ISDN. Currently, the modem supports only V.32bis at 14.4 Kbps, but Eicon says it is planning to provide users with a free software upgrade to V.34 (either 28.8 Kbps or 33.6 Kbps), courtesy of an on-board digital signal processor, sometime next quarter. Also included is a Group III fax modem that can use Microsoft's standard Telephony Application Programming Interface (TAPI) software or Win95's built-in Microsoft Fax client. Eicon provides drivers for Common API (CAPI) 2.0 for ISDN applications as well. There is a virtual COM port for 16-bit applications or for programs that want to send AT comma nds directly to the device. Support also is available for the AT+i commands that set the device's working mode (dat a, fax or voice, for instance), the "B" channel protocol (including X.75, V.110 and V.120) and a variety of other ISDN-specific attributes. The benefit of all of these interfaces is that a variety of software will support the ISDN card. With the optional POTS box (priced at $149), you get two analog jacks for assigning specific directory numbers. Alternatively, you can share directory numbers with one of the built-in logical modems. You can use a standard fax machine to scan and send documents, and use the internal fax device to receive faxes. Harmonic Connections Unlike some other adapters, DIVA Pro does not require an external ring generator for external analog devices. The POTS unit connects to the card via a built-in mini-DIN-type connector and requires no external power. Of course, you must keep the operating system loaded at all times to maintain a dial tone. We tested a beta version of DIVA Pro 2.0 on the most popular ISDN switch types used by North American carriers: Northern Telecom's Nortel DMS-100 running NI-1 code and AT&T's 5ESS switch running native code. Unlike some newer devices, Eicon's DIVA Pro 2.0 doesn't attempt to autodetect the switch or ISDN Service Profile Identifiers (SPIDs). We do not see this as a flaw; based on our lab tests, products that claim to detect switches and SPIDs don't always guess correctly. While we're waiting for the National ISDN Users Forum to settle on standards regarding SPIDs and switch detection, we can simply type in these numbers. Resonant Performance For performance analysis, we connected from our local ISDN Basic Rate Interface (BRI) circuit to an Ascend Communications MAX 4000 router on an ISDN Primary Rate Interface (PRI) circuit. In FTP tests, the DIVA Pro 2.0 averaged transfer rates of 115 Kbps over a dual-channel call. This is an excellent reading considering the TCP/IP and Point-to-Point Protocol (PPP) overhea d will always prevent the achievement of full-line speed (128 Kbps). By enabling MS-Stac compression, we got phenomenal tr ansfer rates--as high as 544 Kbps (a 4.7 to 1 ratio) for very compressible files. |
 |
by Kevin D. Cooke Updated March 7, 1997 |
Best of the Web
Data deduplication: Declawing the clones
Data deduplication is emerging as a critically important new arrow in the storage administrator's quiver to answer hard questions about the increasing problem in storage growth costs.
Compression, Encryption, Deduplication, and Replication: Strange Bedfellows
One of the great ironies of storage technology is the inverse relationship between efficiency and security: Adding performance or reducing storage requirements almost always results in reducing the confidentiality, integrity, or availability of a system.
WAN Optimization Whitelists and Blacklists
Optimization is a fantastic way of saving money and creating really happy customers at the same time, but it doesn't work flawlessly for all applications.
WAN Optimization as a Managed Service: It's Not About the Cost
This insight examines how organizations outsourcing their WAN optimization initiatives to a third-party go about achieving their goals for application performance, reducing operational costs, and streamlining enterprise infrastructure.
