SDN -From What the hell to Yes it is !

SDN is like teenage sex: everyone talks about it, nobody really knows how to do it, and everyone thinks everyone else is doing it, so everyone claims they are doing it…                                                                                                                   –Spoof of an existing saying

About less than 2 years back I read a blog post what the hell is SDN ?  The concept was still in its budding phase with ONF and founding members working on software control of the network operation by standardization of Openflow and related technologies.

This approach by the Networking industry should have been taken long back .Since SDN concept to the Networkers is what Server guys started 10 years back. Continue reading “SDN -From What the hell to Yes it is !”


BGP Address Family Identifiers (AFI) and Subsequent address family identifiers (SAFI)

BGP add

Address family identifier is shared among the BGP peers during the BGP OPEN message as a part of BGP’s Multiprotocol capabilities extension. It is used to describe the network layer protocol associated with the network addresses that follow it during the BGP UPDATE message with the NLRI.

Subsequent Address family identifier provided additional information about the type of NLRI being advertised.

2Here is capture to identify the AFI and SAFI information as shared in the BGP OPEN message.


Continue reading “BGP Address Family Identifiers (AFI) and Subsequent address family identifiers (SAFI)”

Migrating from Cisco to Juniper


Off late there has been a lot of migration from the traditional Cisco oriented networks to Juniper and Alcatel Lucent. Big organizations have migrated from Cisco to Juniper / Alcatel Lucent respectively and the bidding prices for these projects is between 10-100 millions. However deciding factor for these projects was not price alone but the offerings which Juniper and ALU have in comparison to Cisco.
Some of the nodes which have been replaced are
Cisco 6509 to Juniper EX8200
Cisco 3750 to Juniper 3750
Cisco ASR 9K to Juniper MX960
Cisco Nexus 7000 – Juniper 8200 (Strange?)
We’ll I have been a part of migration from Cisco to Juniper for our access and MPLS core ,so could note down certain things which we had to keep in mind for migration preparation.


1.Use the IOS to JUNOS translator (I2J) tool for converting full IOS configuration files into Juniper JUNOS format –This could save a lot of time if you have a large volume, however the tool still throws up some errors and may point you where manual changes may be required. Also interface mapping is required from corresponding to Cisco.


2. Connectivity issues in layer 2 trunk ports between Cisco and Juniper comes up, when Cisco has UDLD configured at its end .So generally disabling UDLD at the B end cisco device access or distribution layer switch may be required in Juniper/Cisco mixed scenarios. Continue reading “Migrating from Cisco to Juniper”

How I get my Youtube & Facebook contents -Google and Akamai CDN

If we see the total internet traffic breakup for any service provider the % of traffic from Google is around 30% ,15-20% of the traffic is from Facebook and sites such as etc. The OTT players such as Google in order to enhance user experience have tried to get as close to the user as possible by direct peering with the regional service providers and provide contents using CDN (Content delivery network) providers. Google is having its own CDN network branded as a service called Google Global Cache (GGC) and Other big players such as Facebook and Microsoft have bought CDN services from Akamai,Limelight etc. Typically any service provider will be having around 40% traffic being served from Google and Akamai combined. So it would be interesting to know how these services work.

Google Global cache

Continue reading “How I get my Youtube & Facebook contents -Google and Akamai CDN”

Nexus 7000 and Catalyst 6500 -Network Designer’s guide

Nexus-6500Its quite a long time since Nexus 7000  has been launched and Catalyst 6500 switches have already proved their mettle in various service provider and enterprise networks.However recently I was asked how would I deploy Nexus 7K and 6500 swicthes in my network provided no problem in CAPEX in procuring the nodes.So best part is to go with what are the differences in offering of the two types of switches by Cisco.

System Construction

The Nexus 7000 and Catalyst, while both highly reliable core switching platforms, have a number of differences in physical construction.

Continue reading “Nexus 7000 and Catalyst 6500 -Network Designer’s guide”

Network and Security Questionaire

1.Broadcast address of
2.Difference between Cisco Nexus 7000 and Cisco 6500.Where will you use it.
3.What are the advantages which Nexus offers in terms of VPC from regular ether-channels.
VPC offers loadsharing along with node level redundancy.
4. Which state does OSPF gets stuck, due to MTU mismatch.

5.What OSPF message carries the MTU size information.
Database discription
6.In RSVP path message ,what is the source and destination IP address at each hop.
7.In which database is the CSPF calculation stored.
Traffic engineering database or ospf opaque database

Continue reading “Network and Security Questionaire”

A day in life of internet



Being a part of ISPs and and as an internet geek for about 6 years now ,I have started relating everything which happens near me to the internet traffic .Whatsapp down –Check their twitter status update ,check their RIPE status .Facebook down -Ahhh screw Akamai guys and blah blah blah .

So if we closely observe the internet traffic trend for any ISP or for the whole world in their respective timezone,it can be related to the lifestyle of the end users. Continue reading “A day in life of internet”

War of the Packet Messaging Applications :Whatsapp,WeChat & Line

India and the other Asian countries are now in a big race to move from traditional voice based mobility services to data based.So has the shift been made in the messaging applications from the circuit switched SMS to the packet switched messaging applications such as WeChat,Line and Whatsapp also not forgetting the reigning apps like Viber.

Sumit Menaria

Whatsapp has currently 400 million  users ,followed by 350 million on WeChat and 300 million users on Line .While the major base of users for Whatsapp is in US and Europe ,WeChat has major users from China and Line from Japan ,mainly due to the country of development of these applications. Continue reading “War of the Packet Messaging Applications :Whatsapp,WeChat & Line”

Should Google/Facebook pay to operators like Airtel, Idea, Vodafone


India has today 13 different telecom operators and more than 100 Internet Service Providers (ISPs).This competition has lead to benefit of the consumer in two ways

1.Improved Quality of service (You have to agree on that :p )

2.Reduction in tariff.

The impact of these two on operators is that they have to put more CAPEX (Capital expenditure)on infrastructure and lesser ARPU (Average revenue per user) . Continue reading “Should Google/Facebook pay to operators like Airtel, Idea, Vodafone”