• Protocols

    ONVIF – Standardizing Network Video & Access Control for Inter-operability

    Network-based IP Video surveillance cameras are great, but they are not like the SIP phones. You can connect a SIP phone to any IP PBX that supports SIP (most of them do) and expect – at the least – all the basic functionality to work. But, you cannot manage IP cameras from different manufacturers (or stream, record/retrieve video) using a single interface/application. You cannot integrate IP security cameras made by different vendors, with an integrated security management system (as long as individual manufacturers don’t offer an interface). This not only creates issues like vendor lock-in, but also makes management of older cameras/cameras made by multiple manufacturers, difficult. ONVIF or Open Network Video Interface Forum…

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  • Protocols

    Wi-Fi CERTIFIED Passpoint: Why is it required for hotspots?

    In our homes/offices, we just need to authenticate with the Wi-Fi network once. After that, we don’t need to authenticate every time we connect to the Wi-Fi network as the computer automatically registers with Wi-Fi network once we switch it on. But this is not possible in public Wi-Fi hotspots, where we need to enter our authentication credentials (username/password) every time we want to connect to the network. Of course, we may visit different public hotspots at different locations, not just one. The Wi-Fi CERTIFIED Passpoint standard enables people/devices to automatically connect to public Wi-Fi hotspots without browser-based user authentication. However, users/devices are authenticated in the background via their SIM…

  • Protocols

    What is LLDP (Link Layer Discovery Protocol)?

    What is LLDP? The full form of LLDP is Link Layer Discovery Protocol. It simplifies the deployment of access devices and enhances endpoint mapping, troubleshooting and management. LLDP is an IEEE standard and hence it can be used in multi-vendor networks (which is the case with most networks). What is the need for LLDP? With all kinds of devices connecting to the network these days, installing, tracking and managing each of them can be quite difficult in large networks. There are many applications for LLDP. Some of them are, To automate the deployment of access devices like IP Phones, Wireless Access Points, etc To help troubleshoot network attached devices To…

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  • Protocols

    LAG (Link Aggregation Group) & LACP (Link Aggregation Control Protocol) – An Intro

    Link Aggregation Groups (LAG) and Link Aggregation Control Protocol (LACP) are methods to provide more than one link between two switches and automate its configuration and maintenance, respectively. Let us look at why LAG/LACP are required and their advantages, in this article. LAG – Link Aggregation Groups To connect two switches, we use a cable to connect two physical ports (one in each of the switches) and configure them as a trunk. But a single trunk has bandwidth limitations. We can use stacking to obtain higher bandwidth, but stacking is mostly proprietary and supports a limited distance. In order to obtain high-bandwidth trunk lines between two switches (or two devices),…

  • Protocols

    TACACS+ – Control and Monitor Access to Network Devices using this AAA Protocol

    TACACS+ is a AAA Protocol (Authentication Authorization and Accounting Protocol) that allows secure user access to network devices by controlling who can access the device and what they are allowed to do, once they access it. Like RADIUS, AAA services are centralized (using a TACACS+ Server) and TACACS+ can even maintain individual command logs. Let us learn more about this protocol, in this article. What is TACACS+ ? TACACS+ stands for Terminal Access Controller Access Control Service + . TACACS and XTACACS were earlier implementations of the same protocol, but they are not compatible with TACACS+. TACACS+ is similar to RADIUS protocol, but there are some noticeable differences. TACACS+ enables…

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  • Protocols

    Neighbor Discovery Protocol in IPv6 – An Introduction

    Neighbor Discovery Protocol in IPv6 is similar to Address Resolution Protocol (ARP) in IPv4. The main purpose of both the protocols is to enable a host (node) to determine the link layer addresses (MAC addresses) of the nodes it wants to communicate with in the local network, and to find out the link layer address of the router though which it can access a node in an external network, so that the actual exchange of messages can happen between the two nodes.

  • Protocols

    What are: Network Ports, TCP & UDP

    Network Ports: When one computing device wants to communicate with a remote computing device, it needs two important parameters to reach and communicate with it. First, it needs the IP address of the remote computing device so that it can locate it over WAN / Internet, and it also needs to know the specific network port it wants to communicate with, on the remote machine. Well, there is only one physical port – The Ethernet port that connects to the computer via an RJ-45 connection. But Network Ports refer to virtual ports that are used by software applications to communicate and interface with the hardware. Each application uses a different…

  • Protocols

    VRRP – Virtual Router Redundancy Protocol provides Network failover/redundancy

    VRRP (Virtual Router Redundancy Protocol) provides fail-over/ redundancy for critical gateway network components like Routers, L3 Switches, Firewalls/UTM's, etc. VRRP eliminates single point of failure at the gateway level and in certain network configurations, it can even provide load balancing along with fail-over. Let us learn more about VRRP, in this article.

  • Protocols

    What is: ARP (Address Resolution Protocol), ARP Cache Table, ARP Poisoning/ Broadcast Storm

    In this article, let us first look at an example of what happens when two computers - CP1 & CP2 try to communicate with each other and through this example, understand what is ARP (Address Resolution Protocol) & ARP Cache Table and why they are required. We will also discuss shortly about ARP poisoning and ARP broadcast storm. Its important to understand ARP to successfully troubleshoot a network.

  • Protocols

    You should know about a new and upcoming Networking protocol called Openflow

    What are the current challenges in a network? Scalability? Disparate and multi-vendor overlay networks? Long time required for re-configuring the global network parameters? Inflexibility? Distributed control and management planes? Openflow is a new and upcoming networking protocol that might just take networking in a new direction altogether by allowing an external controller to control forwarding decisions of a group of switches / network devices. So, the intelligence that gets built into each network switch might get centralized in the future!

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  • Protocols

    NTP – Network Time Protocol

    Network Time Protocol is used to synchronize the time between various devices (clients) in a network as more applications (like precision manufacturing, real time – data, voice) depend on accurate time stamping by multiple systems to function. In this article, let us try to understand the Network Time Protocol better. What is the Network Time Protocol (NTP)? Every network device has an internal battery powered clock which is used to determine the time even when the device is powered off. Each device might be set to a different time (perhaps manually) and the network might be having various devices set to different times. Network Time Protocol (NTP) is an IP…

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  • Protocols

    A Conceptual Introduction to Static Routing, RIP & OSPF

    In large networks, Layer-3 Switches/ Routers are important and inevitable. They help contain the broadcast domain by sub-dividing the network in to various segments. But once a network is segmented, you need to route packets between the various sub-networks. Routing protocols / methodologies like Static Routing, RIP (Routing Information Protocol) & OSPF (Open Shortest Path First) help you to do just that. Introduction: Wouldn’t it be a simpler world if a whole campus could be put on a single network? It would, but it would be a very congested network too! So, when you are planning a network for an enterprise company (or) a huge campus it is a good…

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