Tuesday, July 31, 2012

Wireless Access Point vs. Wireless Router

Is there a difference between a wireless access point and a wireless router?
A wireless access point (AP) connects a group of wireless stations to an adjacent wired LAN. Conceptually, an AP is like an Ethernet hub, but instead of relaying LAN frames only to other 802.3 stations, an AP relays 802.11 frames to all other 802.11 or 802.3 stations in the same subnet.

A wireless router connects a group of wireless stations to an adjacent wired Network. Conceptually, a wireless router is a wireless AP combined with an Ethernet router. A wireless router forwards IP packets between your wireless subnet and any other subnet.

Typically, wireless routers are used in residential and small hotspot WLANs where all users can be supported by one combined AP/router. Wireless APs are used in business and larger hotspot WLANs where many APs are required to provide service -- for example, to cover a bigger area or to support hundreds of users. In larger WLANs, it usually makes sense to have several APs feeding into a single, separate router. Wireless stations can then be treated as one large subnet, which is helpful when roaming from one AP to another. Wireless access controls can also be "concentrated" at one router instead of spread across several independent routers.

Not to confuse you, but there's one more detail I should mention. Most wireless routers are actually low-end firewalls that use Network Address Translation to share one Internet address across several wireless stations. Most wireless routers also include a 4-port Ethernet switch so that you can connect a few wired PCs to your LAN and let them share Internet access too. So, it's really more accurate to say that most "wireless router" products combine the functionality of a wireless AP, an Ethernet router, a basic firewall, and a small Ethernet switch.

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Thursday, July 26, 2012

Different Types of Networks

Local Area Network LAN
A LAN is a local area network that means it is spread over a small area, such as a home, a school, sometime maybe a small group of buildings. In TCP/IP networking, a LAN is often but not always implemented as a single IP subnet. They are often run by a single person and tend to use Ethernet and token ring connectivity systems.

Normally a LAN can handle up to 1024 computers but practically the limit is 256 computers because of the routers and in reality even more less computers are connected in the LAN because of the need.

A basic LAN consist many components and some of them are listed below:
  •     Two or more computers.
  •     Network Interface card or LAN Card in each PC.
  •     Ethernet cable (Cat5, UTP/SPT) cable to connect the two computers.
  •     A hub, switch or router to route or direct the network traffic.
  •     Software for the communication/computer networking

Wide Area Network
A Wide Area Network (WAN) covers a significantly larger geographic area than LANs or MANs. A WAN uses public networks, telephone lines, and leased lines to tie together smaller networks such as LANs and MANs over a geographically dispersed area. Connecting devices in different geographic areas together for information sharing, WANs are an important piece of enterprise networks. For example, consider the VisaNet global network used by Visa International. The VisaNet network connects locations throughout 150 countries to validate and debit credit-card transactions at over 24 million locations. By providing security and simplicity over a standard-based WAN architecture, Visa International relies on their network infrastructure to provide reliable access to merchants who accept Visa credit cards for transactions. 

Metropolitan Area Network
MAN stands for metropolitan area network. As the name suggests a MAN usually have a range of a particular city. They typically use wireless (Wi-Fi or WiMAX) infrastructure or Optical fiber links to interconnect their LAN sites or single computers. In other words it is Local Area Network which is the size of a city.

Technologies that are used to deploy MAN networks in a city or a large area are Asynchronous Transfer Mode (ATM), Fiber Distributed Data Interface (FDDI), and Switched Multi Data-megabit Services (SMDS). Metro Ethernet is a MAN based on Ethernet which is rapidly replacing the older technologies which are still being used in some areas. MAN can link two LANs which done not by cabling long distance areas but rather using wireless alternatives like microwave, radio, or infra-red laser links. Most of the modern companies which deploy MANs for either commercial or private puse, rent or lease circuits from common carriers due to the fact that laying long stretches of cable can be expensive

An intranet is a private computer network built inside Organisation Company or a university. Intranet uses internet protocols with some times wired and sometimes wireless medium network connectivity to securely share part of an organization's information or operations with its employees and students respectively. Intranet can also be described as the organisation own private inter accessible website that holds all the information on running matters of the organisation. The same concepts and technologies of the Internet such as clients and servers running on the Internet protocol suite like Hyper Text Transfer Protocol (HTTP) and File Transfer Protocol (FTP) are used to build an intranet.

The use of intranet is increasing in the cooperate sector day by day for the sharing of information and applications, collaboration between various companies to solve a common problem, teleconferencing, sharing the sophisticated corporate directories sales and Customer relationship management tools like MS project manager etc., to advance productivity.

Intranets are growing rapidly in nearly every part of the world. According to the Intranet design annual 2007 from Nielsen Norman Group the number of pages on participants' intranets averaged 200,000 over the years 2001 to 2003 and has grown to an average of 6 million pages over 2005–2007.

The Internet
The Internet is an example of a network that connects many WANs, MANs, and LANs into the world's largest global network. Internet Service Providers (ISPs), such as UUNet and QWest connect the networks. These providers are responsible for maintaining the integrity of the Internet while providing connectivity between WANs, MANs, and LANs throughout the world. ISPs provide customers with access to the Internet through the use of points-of-presence (POP), also called network access points (NAP), in cities throughout the world. Customers are provisioned access to POPs from their own WANs, MANs, and LANs to Internet access to their users.

In addition to providing customer access to the Internet, ISPs also provide connectivity between each other at "peering points." Large peering points are called metropolitan area exchanges (MAE, pronounced "may"), where ISPs are able to exchange traffic originating in one ISP that is to be delivered to a different ISP. Three major peering points exist in the United States; they are MAE-East in Washington D.C., MAE-Central in Dallas, Texas, and MAE-West in San Jose, California. Qwest maintains a map that shows the connection of these peering points.

More Networks and Cisco Networks Info:

Monday, July 23, 2012

How to Troubleshoot Cisco System's Wireless LAN Module

The Cisco Wireless Services Module (WiSM) is part of the Cisco Wireless LAN Controller family. WiSM works with other Cisco appliances to deliver a wireless solution, which supports voice, wireless data and video applications. The Cisco WiSM integrates into the Cisco Catalyst 6500 Series Switch, a Cisco Catalyst 6500 Supervisor Engine 720 and a Cisco 7600 router. Troubleshooting the WiSM is required when the signals are not getting through to the router. The troubleshooting begins with the WiSM connection.

Things You Need as follows:

Steps to Troubleshoot Cisco System's Wireless LAN Module
1. Type "enable" to enter the privileged mode of the router or switch. The privilege mode will look like this "Router#"; it is the editor mode in which you enter router commands. This privileged editor mode is automatic. All of the troubleshooting commands will occur in privileged mode. For all of these commands, if there is a period at the end, ignore it.

2. Type the command "show version." It is the starting point of any troubleshooting. This displays information relating to the current configuration. One feature displayed is the IOS version running. The WiSM requires a Supervisor 720 on an IOS version 12.2(18). If it does not have 720, or the correct IOS version, there will be problems with the module.

3. Type "show module." Use this command to verify that the Cat6k has a WiSM card and the Supervisor 720 engine. It will also show the number of ports on the card.

4. Type "show wism status" to verify the location of the WiSM module. This information may be useful in locating other configurations on the module.

5. Type "show wism module 4 controller 2 status." This will verify the WiSM status. You will be looking for an "oper-up" information piece to verify the controller's operational status. The module 4 portion identifies the location of the slot in controller 2; it might be different.

6. Type "show interface trunk." This will verify that WiSM and VLANs have trunking defined. If you suspect that a problem is occurring with the VLAN, this would be your starting troubleshooting point.

7. Type "Show etherchannel load balance." This command will verify the correct load balance algorithm. The algorithm should be src-dst-ip. If this algorithm is not present, use the "port-channel load-balance src-dst-ip" command in config mode to reset it.

8. Type "show interface summary" to check the status of the configuration from the WiSM side. Here a summary view of the interface appears. You will see interface name, the port vlan id, the IP address, the type and the application manager.

More Cisco Hardware and Cisco Network Tips...

Monday, July 16, 2012

New Features in Linksys EA4500 Smart Wi-Fi Router

Linksys EA4500 Highlights:
  • New N900 wireless technology
  • Cisco Connect Cloud
  • Gigabit Interfaces
  • USB port for share storage or printer

Features of Linksys EA4500 N900:
  • Ultra-fast wireless speed connectivity (up to 450 + 450 Mbps)
  • Simultaneous dual-band to maximize throughput and help avoid network interference
  • Maximum range and reliability with full 3x3 MIMO antenna array
  • Gigabit ports for speeds 10x faster than Ethernet
  • USB Port to add a range of devices such as storage and printers
  • Cisco Connect Cloud (Available summer 2012) - Get anywhere, anytime access to your home network from a browser or mobile device. Plus, optimize your online experiences with included apps.

I was wondering when Linksys shipped new version E4200V2 router why it didn’t release a brand new product with N900 technology. This E4200V2 improves the performance of the first generation of Linksys E4200 N750 router for faster speed (n900) and optimized for streaming HD video and gaming. Now you have the answer, Linksys introduces new series of Smart Wi-Fi routers including EA4500 N900, EA3500 and EA2700 smart-wifi routers. What’s new with these new lines of products? The answer is that they support the upcoming Cisco Connect Cloud.

Cisco Connect Cloud
Cisco Connect Cloud shortens the distance of your home network as close as your fingers accessing your mobile device, anywhere anytime as long as you can access the internet from around the world. If you can monitor your security surveillance via your network, with Cisco Connect Cloud you can monitor it via the internet from all over the world. Cisco offers new apps to support any types of home smart devices. This is a very benefit feature for traveling users which frequently access their home or small office network when they are away from their network. Netgear with its coming soon product WNDR4700 also offers you Share-Cloud feature, looks like similar feature as Cisco Connect Cloud (available in summer 2012). Netgear doesn’t give a release date yet for WNDR4700, but you can order now for Linksys EA4500 from some stores.
High Speed

Like other new N900 routers, this Linksys EA4500 works on both 2.4GHz and 5GHz bands at the same time delivering wireless speeds of up to 450mbps each band with aggregate bandwidth up to 900Mbps theoretically. You know they won’t reach these speeds in the real world.

All the Ethernet port interfaces are equipped with Gigabit ports including LAN and WAN ports for reliable high speed cable connection; make sure you use CAT5e (extended) or CAT6 UTP cable for best performance. All brand new all-in-one desktop computers include Gigabit Ethernet ports for wired connection, while mostly DOCSIS 3.0 cable modems are also equipped with gigabit Ethernet port you may connect to the EA4500 gigabit WAN port for maximum data rate throughput between modem and router.

USB port is designed with multi functions including hosting the external disk storage, USB printer, and it supports media server. The first generations of Linksys wireless routers including Linksys E-4200 and E3200, you can’t use the USB port to host a printer. Unfortunately there is only one USB port available. So if you require hosting both storage and printer at the same time, you can’t do that. There are some routers available in the market you may consider such as new Asus RT-N66U N900 router with two USB 2.0 ports. You may also compare it with the D-link Dir-857 which includes USB 3.0 port 10 times data rate throughput than standard USB 2.0 port.

The table shows main specs comparison for EA4500 Vs WNDR4700 Vs DIR-857
Linksys EA4500
Netgear WNDR4700
D-link Dir-857
Wireless technology
N900 with 3×3 MIMO antenna (6 internal antennas)
N900 with internal antennas
N900 with smartbeam technology
Gigabit Ethernet
Gigabit Ethernet
Gigabit Ethernet
USB ports
One USB 2.0 for storage or printer, DLNA media server
One USB 3.0 port for additional storage or printer
USB 3.0 port for storage or printer
Other features:
Cisco Connect Cloud
Share-Cloud ready
Ready-share Vault for automatic backup strategy
Time machine support for Mac

SD Card Slot with DLNA compliant

With the included 6 internal antennas and 3×3 MIMO antenna technologies for both 2.4GHz and 5GHz bands, the EA4500 router is very reliable reaching farthest corner of your large house, eliminating the requirement of adding a wireless range extender. To cover the whole home you can place the router in the middle of the house, try not too much obstacles between the router and the clients.

D-Link Cloud Routers
D-link offers cloud routers including DIR-605L (MSRP is only $40) and DIR-600L with mydlink Service – a cloud access to let you access your home network remotely with free smartphone app. with mydlink Service you can manage user control, View Real-time Browsing History, Connect and Disconnect Computer Devices from the Network – all are done remotely from your mobile devices. DIR-605L is based on wireless N300 technology while DIR-600L is N150 router.

The dual version (N600) of D-link cloud router is Dir-826L cloud router 2000 which is also embedded with Gigabit Ethernet interfaces both for wired connection to the LAN and WAN ports. With the built-in high power amplifier, this router covers larger area within the house.

More Related Reviews on Cisco Wi-fi Routers

Thursday, July 12, 2012

How to Configure a Cisco Unified IP Phone 7921 with Call Manager Express?

The Cisco Call Manager Express (CME) software has a new name, Cisco Unified Communications Manager Express. However, it provides the same service, namely IP Telephony that runs on Cisco Integrated Services routers. The Cisco 7921 IP Phone is one of a series of VoIP phones in the catalog. It uses the wireless standards 802.11a, b, and g and it has 2.4and 5 Ghz capabilities. Its other features are a built-in speaker phone and a two-inch display. A diversity antenna is available for better radio frequency coverage.

The Cisco Unified Wireless IP Phone 7921G supports a host of calling features and voice-quality enhancements. The device is an advanced media IP phone, delivering wideband audio capabilities. In addition to wideband audio, Cisco Unified Wireless IP Phone 7921G supports presence, which enables users in a mobile Wi-Fi environment to view the current status of other users. Because the Cisco Unified Wireless IP Phone 7921G is designed to grow with system capabilities, features will keep pace with new system enhancements.
NOTE: More tables to illustrate Cisco 7921 Phones’ detailed features, wireless characteristics, specifications, etc.

Call Manager Express you need first.

Configuring a Cisco Unified Wireless IP Phone 7921 with Call Manager Express Step by Step
1. Type "enable" to enter the router privilege mode. In this mode, you can configure the router and set up the 7921 IP Phone commands. The privilege mode looks like this: "Router#." (Exclude the period.) Privilege mode contains an editor that opens automatically. You type all commands within the editor, but there are different modes depending on the type of command you are typing. You get to those modes automatically by typing the command to initiate the mode. (Note: in these commands, case is not important.)

2. Type "ip dhcp pool VOIP" followed by "network" followed by "option 160 ip lease 8." This command sets up a DHCP (Dynamic Host Configuration Protocol) pool, a leased range of addresses given to network devices. The network term identifies the routing network on the router. The option number identifies the location of the tftp server on the Vlan (Virtual Local Area Network)and where the CME is.

3. Type "Interface Fastethernet0/0" followed by "description Internal Vlan" then followed by "ip address" (Exclude the last period.) Here, you have configured an Ethernet port on the router.

4. Type "interface fastethernet0/0.2" followed by "description VoIP Vlan" with the next command as "encapsulation dot1q 2" and ending with " ip address" (Exclude the last period.) Now you have identified the tftp server, which houses the CME. The next step will set up the 7921 phone.

5. Type "ephone-dn 1" followed by "number 99." Then type "label EntOffice" and ending with "name EntOffice." (Exclude the last period.) The reason you type in "number 99" (not just 99) is that the office phone extension is 99.

6. Type "ephone 1" followed by "description home office" and then "mac-address 0018.95AF.2b73." (Exclude the last period.) The last two commands are "type 7921" and "button 1:1 2:2." (Exclude the last period.) The "mac address" is the phone's serial number address. The type is the 7921 phone system, and the button command maps the phone buttons to the ephone-dn. This allows automatic configuration of the dial peer (the end point of a phone call - where you are calling) and virtual voice ports with the buttons on the phone.

More Cisco Unified IP Phone Info and Tips

Sunday, July 8, 2012

Cisco Catalyst 3750 V2 Series Switches Overview

The Cisco Catalyst 3750 v2 Series are next-generation energy-efficient Layer 3 Fast Ethernet stackable switches. These new switches support Cisco EnergyWise technology, which helps you manage the power consumption of your network, thereby reducing energy costs and carbon footprint.

The Cisco 3750 v2 Switch consumes less power than its predecessors and is an ideal access layer for enterprise, retail, and branch environments. It helps increase productivity and protects your network investment by providing a unified network for data, voice, and video.

Two software images of the Cisco Catalyst 3750 Available
IP Base software includes advanced quality of service (QoS), rate limiting, access control lists (ACLs), Open Shortest Path First (OSPF) for routed access, and IPv6 functionality.
IP Services software provides a broader set of enterprise-class features, including advanced hardware-based IP Unicast and IP Multicast routing, as well as policy-based routing (PBR).

Cisco 3750V2 series is famous for allowing customers to build a unified, highly resilient switching system, one switch at a time, and improving LAN operating efficiency by combining industry-leading ease of use and high resiliency for stackable switches.

So Cisco 3750 version 2 series wins a number of fans among Cisco switch users. If you are willing to choose a Cisco 3750 V2 series, let’s check some hot models of Cisco Catalyst 3750 V2 switch as follows:

·  Device Type: Switch - 24 ports - L3 - Managed - stackable
·  Enclosure Type: Rack-mountable - 1U
·  Ports: 24 x 10/100 + 2 x SFP
·  Power Over Ethernet (PoE): Yes

·  Device Type: Switch - 24 ports - L3 - Managed
·  Enclosure Type: Rack-mountable - 1U
·  Ports: 24 x 10/100 + 2 x SFP
·  MAC Address Table Size: 12K entries


·  Device Type: Switch - 48 ports - L3 - Managed
·  Enclosure Type: Rack-mountable - 1U
·  Ports: 48 x 10/100 + 4 x SFP
·  Power Over Ethernet (PoE): Yes


·  Device Type: Switch - 48 ports - L3 - Managed - stackable
·  Enclosure Type: Rack-mountable - 1U
·  Ports: 48 x 10/100 + 4 x SFP
·  MAC Address Table Size: 12K entries

Related: More Cisco Catalyst 3750 series switches’ details such as prices, availability, Cisco 3750G series, Cisco 3750-X series, Cisco 3750-E series, we can visit Cisco switches—Cisco 3570 series at router-switch.com

Wednesday, July 4, 2012

How to Route Multiple VLANS through a Cisco Aironet 1300?

Enable VLAN or Virtual Local Area Network forwarding through a Cisco Aironet 1300 by connecting to the Aironet Web administration interface. The Cisco Aironet 1300 can bridge network segments and forward VLANs between network segments once the Aironet native VLAN matches that of the switch connected to the Aironet. Configure the Cisco Aironet Native VLAN and VLANs you want to forward using a Web browser.

What You'll Need
Cisco Aironet 1300 configured as a bridge
Cisco Aironet 1300 IP address
Administrator username and password
IDs of VLANs
Native VLAN ID of connected switch

How to Route Multiple VLANS through a CiscoAironet 1300
1. Launch a Web browser, type the Cisco Aironet 1300 IP address into the browser address bar and press “Enter.”

2. Type the Cisco Aironet administrator username and password when prompted and press “Enter.”

3. Click “Services,” “VLAN,” then “New” in the “Current VLAN List” box.

4. Type the Native VLAN ID of the switch connected to the Cisco Aironet 1300 into the “VLAN ID” box. Click to select the “Native VLAN” check box and click “Apply.”

5. Click “New” in the “Current VLAN List” box. Type the ID of a VLAN you want to route through the Cisco Aironet 1300 into the “VLAN ID” box and click “Apply.” Repeat this step for each VLAN you want to route through the Cisco Aironet 1300.

6. Click “Security” in the left pane, then “SSID Manager.” Click “New” in the “Current SSID List” box.

7. Type the SSID or Service Set Identifier for the Cisco Aironet 1300 into the “SSID” box. Click the “VLAN” box, then the Native VLAN number configured earlier. Click the “Apply” button.

8. Click the “Set Infrastructure SSID” drop-down box in the “Global Radio0-802.11G SSID Properties” section. Click the SSID assigned in the previous step and click “Apply.”

More Cisco Aironet 1300 Series Info