Archives: 2008 March

We have all encountered terms like virus, warms, spyware etc many many times in the internet “jungle” without actually distinguishing between them. In this post I will try to define and compare all these malware threats that flow around the computer and internet worlds. Virus: A virus is a malware program that is loaded on [...]

Because my CCNP certification was going to expire recently, I made some research to find out how to recertify. It was a pleasure to discover that by passing any 642-xxx exam, this recertifies you ALL Professional Level certifications (CCNP, CCDP, CCIP, CCSP, CCVP). Of course, the 642-xxx exam has to be a part of the [...]

X terminal Terminal that allows a user simultaneous access to several different applications and resources in a multivendor environment through implementation of X Windows. See also X Window System X Window System Distributed, network-transparent, device-independent, multitasking windowing and graphics system originally developed by MIT for communication between X terminals and UNIX workstations. See also X [...]

WAN wide-area network. Data communications network that serves users across a broad geographic area and often uses transmission devices provided by common carriers. Frame Relay, SMDS, and X.25 are examples ofWANs. Compare with LAN and MAN. WDM wavelength division multiplexing. Multiple optical wavelengths can share the same transmission fiber. The spectrum occupied by each channel [...]

V.24 ITU-T standard for a physical layer interface between DTE and DCE. V.24 is essentially the same as the EIA/TIA-232 standard. See also EIA/TIA-232. V.25bis ITU-T specification describing procedures for call setup and tear down over the DTE-DCE interface in a PSDN. V.32 ITU-T standard serial line protocol for bidirectional data transmissions at speeds of [...]

U interface The interface between the telco and the user, also known as the local digital subscriber line (DSL) loop. UDP User Datagram Protocol. Connectionless transport layer protocol in the TCP/IP protocol stack. UDP is a simple protocol that exchanges datagrams without acknowledgments or guaranteed delivery, requiring that error processing and retransmission be handled by [...]