SD-WAN 360

Episode 2: What is WAN?

January 31, 2019 Season 1 Episode 2
SD-WAN 360
Episode 2: What is WAN?
Chapters
00:00:00
Intro
00:00:26
What is this Episode About?
00:01:02
What is WAN?
00:02:01
Different Types of WAN Connections?
00:02:18
X.25
00:02:41
Frame Relay
00:02:50
MPLS
00:04:05
Who owns these WAN circuits?
00:04:15
What are the problems with WAN circuits?
00:04:43
What type of WAN connections are used Today?
00:05:05
More Details on MPLS: Label Switching, Key advantages?
00:07:18
Different WAN topologies?
00:08:56
Episode Summary
SD-WAN 360
Episode 2: What is WAN?
Jan 31, 2019 Season 1 Episode 2
Rohan Naggi
What is WAN? What are the different topologies for WAN? Why MPLS is so Special?
Show Notes Transcript Chapter Markers

In this episode, we talk about the basic foundation for SD-WAN. We split the SD-WAN word, "SD" and "WAN" and talk about WAN, Different WAN circuits, their topologies, WAN challenges, MPLS and more.

 [00:00] Hello and welcome to the podcast SD-WAN 360. I'm your host Rohan Naggi. SD-WAN 360 podcast is your destination for all things SDWAN, technology that is transforming networking. SD-WAN 360 podcast will help you keep abreast of the latest in the industries and learn from industry experts, their opinion and their experiences. This podcast is all about SD-WAN, software defined wide area networking, but before we get started with SDWAN, let's understand basics and this episode is exactly based on building up those basics around SDWAN.

[00:43] What is WAN? What are the challenges? What are the different types of wide area network circuits? What are the topologies which are supported by the Wan circuits today? Point to point, point to multi-point hub and spoke, so there are many, What is MPLS?

[01:02] SDWAN, Let's separate out SD and WAN, software defined and the wide area networking piece of it, and let's take the first piece which is the "WAN" - wide area network, It is a network or a communication network that is spanning a large geographical area maybe such as across a city, state, county, or even countries. They can be private or public basically to connect smaller networks together and when we talk about these smaller networks, I'm talking about these LAN , so multiple LAN connected via some kind of service provider connection, ISP connection which could be public or private circuits. or even it could be using some kind of a VPN, virtual private network to have a secure communication between these group of networks.

[02:00] Now there are different types of WAN connection. If I go way back, we start off with X.25 connections, frame relay, ISDN and then these leased lines T1, T3 links.

[02:16] X.25 are generally those dial up circuits with 56 kilobits per second. They were used in banking ATM and then the frame relay came and the existence of the frame relay was to overcome some of the issues with x.25.

[02:41] Speed was one of the reason there were higher speeds with frame relay. I'm, and this was way back in 1990's, we're talking about and all these times these T1 , T3 circuits or even frame relay circuits, the focus, the primary focus was the DATA traffic only, and now when the real time traffic started coming in like VOICE and VIDEO traffic, that's were MPLS came to picture (multiprotocol label switching).

[03:11] To support or to handle the real time traf

Support the show

Speaker 1:
0:00
Hello and welcome to the podcast SD-WAN 360. I'm your host Rohan Naggi. SD-WAN 360 podcast is your destination for all things SDWAN, technology that is transforming networking. SD-WAN 360 podcast will help you keep abreast of the latest in the industries and learn from industry experts, their opinion and their experiences. This podcast is all about SD-WAN, software defined wide area networking, but before we get started with SDWAN, let's understand basics and this episode is exactly based on building up those basics around SDWAN.
:
0:44
What is WAN? What are the challenges? What are the different types of wide area network circuits? What are the topologies which are supported by the Wan circuits today? Point to point, point to multi-point hub and spoke, so there are many, What is MPLS?
:
1:03
SDWAN, Let's separate out SD and WAN, software defined and the wide area networking piece of it, and let's take the first piece which is the "WAN" - wide area network, It is a network or a communication network that is spanning a large geographical area maybe such as across a city, state, county, or even countries. They can be private or public basically to connect smaller networks together and when we talk about these smaller networks, I'm talking about these LAN , so multiple LAN connected via some kind of service provider connection, ISP connection which could be public or private circuits. or even it could be using some kind of a VPN, virtual private network to have a secure communication between these group of networks.
:
2:01
Now there are different types of WAN connection. If I go way back, we start off with X.25 connections, frame relay, ISDN and then these leased lines T1, T3 links.
:
2:16
X.25 are generally those dial up circuits with 56 kilobits per second. They were used in banking ATM and then the frame relay came and the existence of the frame relay was to overcome some of the issues with x.25.
:
2:41
Speed was one of the reason there were higher speeds with frame relay. I'm, and this was way back in 1990's, we're talking about and all these times these T1 , T3 circuits or even frame relay circuits, the focus, the primary focus was the DATA traffic only, and now when the real time traffic started coming in like VOICE and VIDEO traffic, that's were MPLS came to picture (multiprotocol label switching).
:
3:12
To support or to handle the real time traffic like audio video, so to support MPLS protocol, leased lines, Metro Internet came to existence. If you remember of T1 , T3 circuits, T1 circuits were 1.54 megabits per second, mostly for the home use. For corporate T1 was bumped to close to 45 megabits per second and David called as the DS3 circuits or what we call it as DS3 digital signal 3 circuits, which was the primary use case for the corporate network. OC3 and OC12. These are the different type of WAN circuits. OC3 with 155 Mbps. OC12 with around or 600 Mbps megabits per second.
:
4:07
Typically a service provider, owns these Wide area networks connections, WAN Circuits. What are the problems with these WAN? Loss of connectivity, Security concerns are there on public internet, let's say application performance at the same time, Application contention. There are so many applications coming out of the LAN and going onto these limited bandwidth connections, so applications are facing the contention.
Speaker 1:
4:44
Lets fast forward and talk about what type of WAN connections are used today? mpls, dark fiber, metro ethernet, broadband, dialup, even today legacy T1 , T3 links are used , cable modem, fiber optic connections,ISDN.
Speaker 1:
5:07
MPLS, Multi Protocol label switching. As the name suggests, label switching. It means each device in that mpls network is putting a tag and that tag is used to identify where the next hop is, where to redirect the packet, the traffic to.
:
5:30
let's understand it better. So mpls is a way to ensure a reliable connection for real time applications , you remember for x.25, the focus was data traffic, with MPLS, the focuses is Real time application traffic. So basically MPLS is providing you with a vpn. Virtual private networks, Quality of Service (QoS), traffic engineering and we've talked about this traffic engineering, but this label switching what we are talking about, so each router or device in the mpls network attaches a label , the packet with the label, that label has enough information on how to identify the next hop instead of going and reading the entire table the device/ router in this case can understand the information from that label, so these labels are used to direct data from one node, one network, to other device based on the shortest part label, rather than, again reading the long network address. T
:
6:44
his avoid complex look up in the routing table because each router or switch has that big routing table and that speeds up the traffic flow. The key advantage for mpls service is reliability, reliable connection from customer point of view around the packet for the service provider network, the CE, the PE router and the service provider network will take care of routing packets, quality of service, but remember with mpls the cost is high.
:
7:19
There are many topologies, let's talk about some of them. Point to point hubspoke topology, full Mesh , dual home,
:
7:30
so let's talk about time to point. Point to point our dedicated connections like offered from lease line, T1 link , E1 link. hub spoke, topologies is point to point, but multiple point to point connection, so basically all the spokes in this case, branch site connections typically connecting to a centralized site. In this case, the centralized site would be a data center site or a hub site, so all the communication which has to happen between branch sites, they have to go through the data center where the hub device is. So , for point to multipoint or for hub and spoke topology , All the spokes will first redirect their traffic to the hub because hub has all the information on where the spoke is . so they can redirect those packets from spoke-1 to spoke-2.
:
8:24
full Mesh, full mesh using virtual circuits. In this case now spokes can talk to each other. They don't have to go all the way to the hub site and then get the traffic redirected. Dual home spokes have multiple connections. Maybe all public circuits are a mix like public private circuit, and here the configuration can be complex because you're already using different vendors, different service providers, different configuration has to be there for public circuit and private circuit.
:
8:55
To Summarize, We talked about wide area networking. What are the different type of WAN circuits, ISDN , frame relay, X.25 , T1, T3 lines,dark fibers, MPLS Remember the MPLS focuses is vpn, virtual private network traffic engineering, Quality of service, this technology is a good fit for Real Time Application traffic. It's expensive. At the same time, we've also talked about different topology, point to point , Hub and Spoke.
:
9:32
In the next episode we'll talk about the SD software defined networking. Bye for now. Thanks for tuning to SDWAN 360 podcast, I am your Host Rohan, from the heart of Silicon Valley. Bye for now.
What is this Episode About?
What is WAN?
Different Types of WAN Connections?
Frame Relay
Who owns these WAN circuits?
What are the problems with WAN circuits?
What type of WAN connections are used Today?
More Details on MPLS: Label Switching, Key advantages?
Different WAN topologies?
Episode Summary
×

Listen to this podcast on