Lightwave

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I was following some lightwave webminars and articles these days closely. Lot of things displayed there make me think where the future telecom would be ..! decade started with 1G and already there are trials of 500G. I guess the near life like experience, which is currently present only in corporate will be available to the public. Though in ads of 3g i see them, but not that satisfactory. Since I work in a wider spectrum knowing the placing of the products and the issues faced, it really looks interesting how all this development happened in 2-3 decades. Can’t imagine like the fiction author Sujatha who predicted lot of current advancements. More and more telecom startups are coming up, and more and more are acquired by the giants like Cisco and Ciena especially in the optical arena. Would post a detailed info after observing their moves in the coming year, but for sure their share in all the areas are increasing providing the customers with variety to choose from.

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STP & RSTP

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What I learnt (rather revised today!) is about STP and RSTP..

STP is Spanning Tree Protocol.. which is used to reduce looping within the network. RSTP is an advanced version kind ..

The basic difference between the 2 is that, RSTP as the name suggests wil be reducing the convergence time which is min 50 sec n STP. But here it can be less than even 2 seconds.. interesting.. jus enabling the portfast feature in the edge links and changing the listening state to discarding state is the mail source of this time reduction.. and also introducing the backup ports and alternate ports form a major turn around in RSTP, whereas STP uses only forwarding and blocking ports..

Concepts regarding election, root bridge sounds pretty interesting, since never imagined such a society where the looser backs the winner.. may b a ideal society..?!!

Lot of commands are there to configure the same, which I need to chk it out once before I take up the exam!

Frame Relay

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Was not much comfortable with FR till yesterday, now am ok with it, jus went thru few links and a video tutorial of the same and chked how things work in the configuration stuff too… Though learned about FR long back in college days, was not sure how and where things are working with it, so it was a vague topic for me. Now am ok with the basics of frame relay and even the basic show/debug commands of the same.

These links are bit more helpful I guess..

http://www.cisco.com/univercd/cc/td/doc/cisintwk/ito_doc/frame.htm

http://www.cisco.com/warp/public/125/12.html

Both are from cisco docs, but they are more elaborate..

Jus wanted to summarise wat i learnt reg FR

  • Its a packet switching N/w WAN protocol
  • Its based on STDM
  • X.25 is the first STDM protocol and FR was developed after it in 1984
  • It was standardised by 1990 when FR Consortium was formed, but it was not internationalised that time, later ANSI and ITU-T took it up and standardised it for international usage and privided specifications
  • DTE/DCE -> formed the major terminologies, where
    • DTE – Data Terminal Equipment – usually a router (L3)
    • DCE – Data Communication Equipment – usually a switch (L2)
  • AL – Access Line connects the DTE to DCE
  • TL – Trunk Line connects the DCE to other DCE
  • VC – Virtual circuit – end to end logical connections
    • SVC – Switched VC
    • PVC – Permanent VC
  • Encapsulation
    • CISCO specific
    • IETF specific
    • diff is pkt type is specified in cisco specific encapsulation
    • DLCI – Data Link Connection Identifier – 10 bits – 16 to 1007
    • CIR – Committed Information Rate

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Commands

  • encapsulation frame-relay
  • frame-relay interface-dlci (16-1007)
  • Show commands
    • show interface serial()
    • show frame-relay lmi
    • show frame-relay pvc
  • Debug Commands
    • debug frame-relay events
    • debug frame-relay packet
    • debug frame-relay lmi

Need to chk it out in the simulator.. think its moving on fine.

Next need to read abt IP addressing, routing ..

RFCs

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I am not that gud in networking protocols stuff.. but thats wat is required to get through the basics in ccna, so started reading rfcs, so that i get a clear picture of wat is it and wat its not…

Planning to read RFC 791 and 793 today .. will keep posting about wat i read before go and hit the bed…

My Comment… Spam?

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Your IP address (59.92.80.29) is detected as an open proxy (a common source of spam) so comment access is denied. If you do not believe you’re accessing the net through an open proxy, please contact your ISP or this site’s tech support to help resolve the problem.

Got this error when trying to post a comment in chaku’s blog

Dono why it was like this, my ISP is none other, BSNL guys. Was not sure, wat is open proxy, just checked out wiki and got the basic info abt the same. All I know is a proxy server is the one in which clients connect to Internet indirectly with diff ips. In office also I use proxy to connect to internet. Dono why BSNL is routing thru open proxy :-S

Am not able to post any comments to livejournal, wordpress (caught as spam!), blogspot allows me since am registered there.. let see, why this happens. Doing some reading abt it. Anyone who knows, jus pass me a link, so that I can chk it out, why I get such errors.. 😦

Learnt a good deal abt DNS and BIND

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Staying in home, moving around 3 or 4 rooms makes me really sick.. so thought I could dwell into something I barely know.. how DNS exactly works.. and hows BIND its enhanced version works…

DNS came into picture becas ARPANET failed becas of its HOST.TXT file issue. The issue is there were name collisions which was not handled efficiently. Traffic and load were not really maintained properly in ARPANET, since it was basically designed for smal netework, when promoted to host internet, things started screwing up. Finally it missed (can we say messed? ) consistency levels…

So, here comes Paul Mockapetris, released RFCs 882 & 883 [ which later developed into RFC 1034 & 1035, with enhancements ]

Hmm.. what exactly is DNS? nothing serious, its a distributed DB 🙂 based on client server technology. Server is referred as Name Server, and client as Resolver..

Domain
|
|
——> Hosts
|
|
——> Sub-domains

First implementation of DNS was JEEVES by Paul as we know.. and the later implementation of DNS is BIND…
So wats BIND?
BIND => Berkley Internet Name Domain, started out in BSD 4.3 by Kevin Dunlap. Now its maintained by Internet Software Consortium

OK..lets get into something thats more interesting.. leaving behind all these history stuff..

How are things organised and working out in DNS?
So its similar to unix file system type of listing..
top-level domian names, followed by second level domain ..

top-level domain names like (.com, .org etc.. ) use the delegation model to traverse through the second level and further down..
So how does managing a domian, subdomain take place.. well its delegated.. the management is like this..

consider a site archu.blogspot.com
.com is the toplevel domian which delegates the google guys to manage blogspot , which is a subdomain, whereas, blogspot guys delegate archu ( its me!! ) to manage that particular page.. its that way as simple as it is.. no collisions..

Sounds fine.. but wat is data is lost in toplevel domain..?
here comes the kool back up strategy they follow… they have a primary master and secondary master to take care of the same..
check out the RFCs for more detailed info reg the same 🙂

Transaction Language 1

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Nowadays Iam more towards TL1 language which acts as an interface between networking equipments and user. It helps in great way to interact with the equipment. There are only few notable sites for TL1 in web and they are..

TL1
TL1Guru

This is an interpretted language and its bit simple if we understand the network equipment’s architechture.

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