Networking Tips Tricks

Broadband Wireless Access Technologies  Local Multipoint Distribution Services (LMDS)  Multi-channel Multipoint Distribution Services (MMDS)  CDMA EvDO/EvDV  W-CDMA  TD-CDMA  WiMAX What is WiMAX? Worldwide Interoperability for Microwave Access (WiMAX) is the common name associated to the IEEE 802.16a/d/e standards that originally covered the Wireless Local Loop technologies with radio spectrum from 10 to 66 GHz. Why WiMAX? Standard based  Lower Cost  Ensures compatibility and interoperability  Better Performance & Coverage

 Ways of providing Broadband Access? Copper Wire (DSL)  Optical Fiber Cable  Wireless Access System.  Satellite Communication System  Why Broadband Wireless Access ? Lower Capital Expenditure  Lower Operational Expenditure  Faster Deployment Time  Scalable & Easy Relocation

Q: What is Broadband? Ans: Broadband comes from the words "broad bandwidth" and is used to describe a high-capacity, two-way link between an end user and access network suppliers capable of supporting full-motion, interactive video applications.  A way of transmitting large amounts of data, voice, and video that is greater than telephony networks. A term for high-speed, high-capacity Internet and data connections.  It is type of data transmission in which a single medium can carry several channels at once including voice, data and video simultaneously. It is also a general term for different types of high-speed, high-bandwidth connections to the Internet, including Cable and DSL.  Broadband" refers to a type of network connection that supports a very high bit rate, as opposed to "narrowband," which supports a lower bit rate. The higher the bit rate, which is a measure of speed of transmission of bits per second (bps), the faster the transmission will occur in a...

16-QAM,64-QAM The number before QAM (for example 16QAM) refers directly to the number of decision points in the constellation. Meaning, 256QAM has 192 more decision points than 64QAM. The number before QAM is also always a power of two. (EG. 2^6=64QAM)  There are several trade offs to this:  The more Decision points, the more throughput per channel.  The more Decision points, the more susceptible the channel is to noise (as the decision boundaries get smaller to accommodate more decision points, it becomes harder to distinguish which boundary the point was intended to lie in).  More Decision points=More Bandwidth=Higher susceptibility to noise or poor signal (the same applies inversely as well).  At best, it'll enable either to:  Deliver the same number of customers incrementally faster speeds.-or-  Deliver a larger number of customers the same speeds as before.

NDR (Non-Deliv ery report) List of Codes and their meanings 4.2.2 The recipient has exceeded their mailbox limit. It could also be that the delivery directory on the Virtual server has exceeded its limit. (Default 22 MB) 4.3.1 Not enough disk space on the delivery server. Microsoft say this NDR maybe reported as out-of-memory error. 4.3.2 Classic temporary problem, the Administrator has frozen the queue. 4.4.1 Intermittent network connection. The server has not yet responded. Classic temporary problem. If it persists, you will also a 5.4.x status code error. 4.4.2 The server started to deliver the message but then the connection was broken. 4.4.6 Too many hops. Most likely, the message is looping. 4.4.7 Problem with a timeout. Check receiving server connectors. 4.4.9 A DNS problem. Check your smart host setting on the SMTP connector. For example, check correct SMTP format. Also, use square brackets in the IP address [197.89.1.4] You can get this same NDR error if you have been deleting...

Squid Configuration file Requirement: option file which consist of all squid configuration options. Solution: Squid Cache: Version 3.0.PRE4-20060804 configure options: '--build=i386-redhat-linux' '--host=i386-redhat-linux' '--target=i386-redhat-linux-gnu' '--program-prefix=' '--prefix=/usr' '--exec-prefix=/usr' '--bindir=/usr/bin' '--sbindir=/usr/sbin' '--sysconfdir=/etc' '--includedir=/usr/include' '--libdir=/usr/lib' '--libexecdir=/usr/libexec' '--sharedstatedir=/usr/com' '--mandir=/usr/share/man' '--infodir=/usr/share/info' '--exec_prefix=/usr' '--bindir=/usr/sbin' '--libexecdir=/usr/lib/squid' '--localstatedir=/var' '--sysconfdir=/etc/squid' '--enable-poll' '--enable-snmp' '--enable-removal-policies=heap,lru' '--enable-storeio=aufs,coss,diskd,null,ufs' '--enable-ssl' '--with-openss...