QOS - Quality of Service

Quality of Services:

QOS is a technique which enables network administrators to deal with ,majorly bandwidth related issues,jitter, delay etc. QOS provides the flexibility that ,we can classify and prioritize different applications running in network as per our requirement to guarantee the performance of those applications.

QOS is majorly used in VOIP, Video streaming, Business critical applications,etc.

Understand the use of QOS in network:

Imagine a enterprise network which is having presence is all over the country for its Business. But we majorly see that every location will have difference in bandwidths depending upon the importance of location like Tier-1, Tier-2, Tier-3, etc.

The requirement of Business is , at any point of time all the important applications should run for business work. Many times due to heavy usage of link by some particular application, other applications will be affected. So by using QOS we can classify applications as per our need and prioritize as per requirement.

This results to control over application flow from router’s outgoing interface. For example we can set priority like 1-Voice,2- Video, 3-Business Applications (SAP,Citrix),4-etc. Before application will go out from outgoing interface, first it will classify the packets according to our classification rule and process the packets according to configured priority.

I hope this description will help you to have overview of QOS. We will see QOS tools/techniques in upcoming posts.

MPLS - Control Plane and Data Plane

MPLS Architecture – Control Plane and Data Plane (Forwarding Plane)

Control plane: Responsible for Exchanging layer 3 routing information and labels.

Control plane consists complex mechanism to exchange routing information such as OSPF, EIGRP, IS-IS, and BGP and to exchange label such as TDP, LDP, BGP and RSVP.

Data plane: Responsible to forward packet based on labels and IP header.

Data plane has simple forwarding engine it maintains LFIB and FIB.

Control Plane:

Routing protocol: Responsible for exchange of routing information .It prepares IP routing table.

IP routing table: Responsible to build IP forwarding table (FIB) in Data Plane (Forwarding plane).

LDP: Responsible for exchange of labels between the peers. After exchanging the labels with LDP peer LFIB is formed in Data Plane (Forwarding Plane).

Data Plane:

1.  As the IP packet comes in it will do a IP routing lookup and check is any label is associated with particular FEC. If yes then label is imposed in the packet and process by LFIB as labeled packet.
2. If no label is associated with IP Packet then it is processed as normal IP Packet by FIB.
3. If incoming packet is labeled then by using LFIB the label is swapped and the packet is processed

Note : figure is from INE blog *