A 16 minute video on BGP without explaining how it actually works... For God's sake, give the man a marker and a brown piece of paper and let him draw a few examples.
This explanation is in dire need of evolving drawings to illustrate the examples he's using. He is making gratuitous use of his hands, which just shows the need for a visual aid.
I feel like the title is misleading. This is really just a glimpse at the math that's used for various network algorithms. This is not a video on 'BGP the routing protocol'. For example, the "min/max bandwidth" concept is not a easily done (or commonly used) feature of BGP. That's primarily an EIGRP thing. The first thing anyone does when they want to explain BGP is compare/contrast to traditional IGP routing protocols. He's rambling on about semi-rings and algorithms. What's crazy is that BGP is actually the most mathematically simple routing protocol. In most cases routing policy and network preferences are enforced using manual human intervention using various "kludges" like community strings and AS-path prepending. All this talk about semirings is just out of place.
I agree with the most of the comments saying Dr Tim Griffin kind off went too deep into theory why BGP was created, rather than talking about how it actually works which was what I was expecting out of this video. But I did ended up learning a few things along. The main point I got out of this is that BGP routing is usually managed by network engineers enforcing static rules rather than some implementation of dynamic routing mechanisms. We have not yet come up with a model that will follow the whole political aspect of Autonomous Systems and agreements between them. Correct me if I'm wrong.
At first, I thought the same as those guys in the comments below. Lector packs lots of contents in the shortest videos, lacks illustrations etc. And THEN I've watched a series of Computerphile after taking a 4:20 hit. The change was drastic! These series are not aimed to explain how it works. They are aimed to deliver an impression. A background that will make pure theory much closer to you than before. You see, networking and Internet theory has lots of horrors within. Something needs to make those horrors familiar or even appealing. This series does it perfectly.
+ketilsin Or just done a multiple part video. There have been multiple part videos for much simpler concepts than BGP. I am 11 minutes in and he only just broke into what BGP is actually doing.
At 12:20 why does the neighbour pick the pink path? Surely as he iterates along the path he sees that your link is weak so also breaks ties using shortest path?
That's absolutely correct. I was about to comment the same thing. His example is not valid. Perhaps if the neighbor only checked the capacity to your ISP or something??
Also, if his argument about capacity then breaking ties with distance is correct, then the same problem will happen when using distance first!!! Because if you have to break a tie, you need to use capacity...
+Harrison Harris The neighbour probably didn't see the other path, so had no idea that it was the better path. Why would he check for more paths when he has already found one path which works. The 2 neighbours might also not be following the same rules, one going for high capacity, and the other going for shortest distance.
Nice video explaining BGP in high level, generalization of Dijkstra, BGP disagreement, and that routing protocols don't take congestion into account so ISPs need to adjust weights for load balancing.
I think some people might be confused in the video. He is basically(not really) explaining the BGP algorithms and its architecture theories. And also Dr Tim covered couple courses that takes a while to study. This is basically CCNP level or a third/fourth year computer science course in BSc.
+Daniel Page (Entertainmentwf) Only speaking from A-level maths experience here, but in the D1 (Discrete 1) module we referred to non-directed edges as arcs. It may be terminology that varies across the world.
I sadly have to agree with many, that this was a bad explanaition for BGP. The Routing Video that was linked by you was much better in explaining what BGP actually does. The whole "semi-ring"-thing / algebraic constructs is something no one will understand from his explanaition alone without some basic university math course / real interest in the topic and is mostly irrelevant for the idea what BGP does. So i think it would have been better to make some multipart with "general idea of BGP - why, how", "djikstra / bellman-ford", "delve into its maths", where the pure math part (i would love to see it, but i have only a really broad idea of what he was actually telling me) just expects some previous knowledge about algebra.
Which has nothing to do with what's discussed in the video but is driven in large part by the fragmentation of the IPv4 address space because of address shortage.
it was sad at the end when the red frog had to leave the green one due to commitments with family at home.... on the plus side they will be able to keep in touch over the internet once someone finds out how BGP works..
+Adi Serghei Who is being sarcastic? It was a qualitative explanation, but anyone with a basic math background can understand it in a deep way. If you can understand what he said you can take it to other context. If you want you can take basic linear algebra and apply it to any network.
+Adi Serghei it was a great video, I enjoyed it. Should have been accompanied with some more Numberphile videos though. And maybe splitting the subject into more videos.
+goeiecool9999 A gree, BGP was never actually explained, that's what I came here for. Instead he explained algebra I already knew and basic SP algorithms :|
I think the title was a bit misleading on this one. Or I completely missed him BGP. I think something more general such as the problems with internet routing would be more appropriate.
Should be titled "Part 1", since we haven't even *gotten* to any of the meat (or even skin!) of BGP yet. BTW, official ISP network administrator here! I'm the guy who has to adjust the weights if/when things congest, but of course the *real* meat of my job is to adjust/upgrade/supplement the *links* and/or re-engineer the routing graph well in advance of real bandwidth demand mustering up enough oomph to congest them. xD
My apologies Dr. Griffin, but I can't find any comments of yours above or below in this comment section aside from "see my comment above" written in reply to a few other folk as well? :o - Do you have a link you could share to said comment? :3
As an American, people chide me too when I say "root er" (router) or "roots" (routes). Makes more sense to me. People did not get their kicks on "Rowt" 66.
+rchandraonline In the context of networking, my preferred pronunciation is 'rowt' to avoid ambiguity with 'root' which has enough meanings in Unix already.
"Let me explain BGP" -> mildly interested "So, semirings..." -> Oh, I know this! So they're finally doing some real computer science here! Go on! "But we can't use them" -> So... I guess you will come back to them, right? "bla bla bla" -> Uhm... Any more content, please? outro -> Wtf just happened?
8 років тому
I often hear that "there is no centralized control over the Internet", but still there is some that can sell domain names, some that control the top domains, whatever I want to do on Internet it always end up in that I has to pay someone a huge amount of money. If no one controll it and no one owns it, where do the money goes and what shall I do if I want to become a ISP? Thank you for a great channel and interesting videos.
+Jim Engström Run some cables down between your neighboring cities/countries and purchase some expensive routing equipment and then you will get 'free' internet... sadly you can only communicate with those on your network though. But you might be able to pay another ISP to forward your traffic the 'last mile' to their customers.
I hadn't thought of Dijkstra's algorithm as the source of defining a semiring on paths in a directed weighted graph (does summing edge weights and min'ing totals really form a semiring for any set of edge weights in a given graph? Any set of numbers?) Conversely, it makes sense that alternative strategies like that of optimizing for capacity might not behave the same. Indeed max of the mins of edge weights is not necessarily the min of maxes. But what does any of this have to do with BGP and other protocols?
Someone correct me if i'm wrong here, but wouldn't getting min bandwidth from each path and breaking on shortest distance resolve the distributivity issue? in the example given, both clients would choose the high bandwidth path, as the bottleneck was higher bandwidth than the other hop on the shorter path. I think this checks out in other scenarios too... but if so is probably obvious and i should just read up on semi rings in shortest path algorithms.
+Mladen Mijatov Only partly his fault, that topic (in this depth) is just way to large and abstract for such short a video. Thats semesters of computer science for people without previous knowledge.
Ae Norist you are right, but I can't help but feel it could have been presented in a better way even at the cost of being too abstract. Granted subject is a complex one and if nothing else he should have given enough knowledge to spark an interest for further research.
Beg to differ. It usually ranges from simplistic to very easily explained complexity (imho), which is why it might reach the audience it does, which is a good thing.
One thing I took away from this is that it could be beneficial to general population to break up commercial ISPs/their networks and transfer control to the (international) public (e.g. creating a "Euronet" in the EU). Am I missing some relevant info that makes this a bad idea?
I really thought wtf is he on about with his abstract operators then he said like yeah max and min and I was like ooooooh like that! Makes sense to use minimal values along a patht to determine the best path. A path is only as fast as it slowest link anyway.
probably the worst explanation of routing protocols I have ever heard. homeboy obviously never picked up a Cisco in his life. yes, least cost routing works on BGP to.
+Penny Lane he's a well noted academic but I've found that shows no correlation with teaching quality. He taught our courses on databases, and compiler construction, but neither of those seem to be his main area of expertise (networking and all that).
+Ang Ma He's certainly better at explaining things than some lecturers I've had, though I admit that I'm quite familiar with this subject area so I didn't find it too hard to keep up. He is trying to explain a lot of concepts for a fifteen-minute video, though, so I don't really think it's fair. It is a bit odd, the whole thing of having researchers giving lectures. They're not necessarily skilled at imparting knowledge in spoken form, and a lot of them would probably much rather be getting on with research.
But BGP won't let me be So everybody just follow me Cuz I'm the shortest path to your ISP So everyone learn BGP! Dan an an ar na, Dan an an ar na, Dan an an ar na, na na na na! (To the tune of Slim Shady Woithout Me!)
Misleading title. I did not learn about BGP after listening to him for 16 minutes. The title should change to " How to make a long speech in any topic!"
Very good video, but I guess it should be in a place like Numberphile2-equivalent of Computerphile. Many people didn't understand and are complaining about the professor, who did a great job in my opinion.
A 16 minute video on BGP without explaining how it actually works... For God's sake, give the man a marker and a brown piece of paper and let him draw a few examples.
My thought exactly
see my comment above ....
He focused on bgp architecture algorithms not the definition
This explanation is in dire need of evolving drawings to illustrate the examples he's using. He is making gratuitous use of his hands, which just shows the need for a visual aid.
+Celebris Nexterra there are times on this channel when the cameraman asks questions so simple it makes you cringe. On this video I miss them so much
I feel like the title is misleading. This is really just a glimpse at the math that's used for various network algorithms. This is not a video on 'BGP the routing protocol'. For example, the "min/max bandwidth" concept is not a easily done (or commonly used) feature of BGP. That's primarily an EIGRP thing. The first thing anyone does when they want to explain BGP is compare/contrast to traditional IGP routing protocols. He's rambling on about semi-rings and algorithms.
What's crazy is that BGP is actually the most mathematically simple routing protocol. In most cases routing policy and network preferences are enforced using manual human intervention using various "kludges" like community strings and AS-path prepending. All this talk about semirings is just out of place.
See my comment above ....
@@timothyggriffin what comment "above"? That didn't age well. The way these get sorted or pinned may and have changed over time.
Yeah I was here for the actual protocol and not how it came to be although this was very interesting
I agree with the most of the comments saying Dr Tim Griffin kind off went too deep into theory why BGP was created, rather than talking about how it actually works which was what I was expecting out of this video. But I did ended up learning a few things along.
The main point I got out of this is that BGP routing is usually managed by network engineers enforcing static rules rather than some implementation of dynamic routing mechanisms.
We have not yet come up with a model that will follow the whole political aspect of Autonomous Systems and agreements between them.
Correct me if I'm wrong.
he literally explains that in the beginning
Google/UA-cam has a sense of humour recommending this today lol
too bad i had to search for it after the incident
If anybody is confused, its because he sorta covered a whole course in 16 minutes, and its like a 3rd or 4th year CS course.
Maybe half a course...
At first, I thought the same as those guys in the comments below. Lector packs lots of contents in the shortest videos, lacks illustrations etc. And THEN I've watched a series of Computerphile after taking a 4:20 hit. The change was drastic!
These series are not aimed to explain how it works. They are aimed to deliver an impression. A background that will make pure theory much closer to you than before. You see, networking and Internet theory has lots of horrors within. Something needs to make those horrors familiar or even appealing. This series does it perfectly.
hmm.. not sure if he actually explained anything here
Would be nice to have some examples with his abstracted explanation.
+ketilsin Or just done a multiple part video. There have been multiple part videos for much simpler concepts than BGP. I am 11 minutes in and he only just broke into what BGP is actually doing.
see my comment above ...
Right now Facebook employees are here
3:54 it's not a restriction: it's a preference. Many of the other paths still exist and are an option to be selected in case an other fails.
At 12:20 why does the neighbour pick the pink path? Surely as he iterates along the path he sees that your link is weak so also breaks ties using shortest path?
That's absolutely correct. I was about to comment the same thing. His example is not valid. Perhaps if the neighbor only checked the capacity to your ISP or something??
Also, if his argument about capacity then breaking ties with distance is correct, then the same problem will happen when using distance first!!! Because if you have to break a tie, you need to use capacity...
+Harrison Harris The neighbour probably didn't see the other path, so had no idea that it was the better path. Why would he check for more paths when he has already found one path which works. The 2 neighbours might also not be following the same rules, one going for high capacity, and the other going for shortest distance.
+THESothatsit Using your logic he would have to check every single path to make sure that the path he found is the best path.
I understood some of these words.
xD
This video is a great example of how not to explain something in 16 minutes.
Nice video explaining BGP in high level, generalization of Dijkstra, BGP disagreement, and that routing protocols don't take congestion into account so ISPs need to adjust weights for load balancing.
LOVE the Kylie & Jason illustration used for Dr. Griffin's "neighbours" anecdote. Another good one, Computerphile!
Hi to all of you coming here in 2021 to understand what was going on at Facebook 👋
Lol hi! Exactly why I came here
we are united in our desire to understand how stuff works
same reason
Time to learn more!
UA-cam algorithm be like
I think some people might be confused in the video. He is basically(not really) explaining the BGP algorithms and its architecture theories. And also Dr Tim covered couple courses that takes a while to study. This is basically CCNP level or a third/fourth year computer science course in BSc.
I'm at 9:14 and I still have no flipping idea what a semi-ring is...
+Kevin Klika I think doctors prescribe them if you are having trouble in the bedroom.
ah makes sense, I didn't think the video was terrible but it was a bit messy it needed more visual aids.
The only minor flaw I noticed is that while the speaker said arc (directed edge), the visualization showed an edge. Aside from that, very nice.
+Daniel Page (Entertainmentwf) Only speaking from A-level maths experience here, but in the D1 (Discrete 1) module we referred to non-directed edges as arcs. It may be terminology that varies across the world.
Facebook brought me here. Well... Sort of.
I sadly have to agree with many, that this was a bad explanaition for BGP. The Routing Video that was linked by you was much better in explaining what BGP actually does.
The whole "semi-ring"-thing / algebraic constructs is something no one will understand from his explanaition alone without some basic university math course / real interest in the topic and is mostly irrelevant for the idea what BGP does. So i think it would have been better to make some multipart with "general idea of BGP - why, how", "djikstra / bellman-ford", "delve into its maths", where the pure math part (i would love to see it, but i have only a really broad idea of what he was actually telling me) just expects some previous knowledge about algebra.
I've been waiting for this since BGP exceeded 512k and crashed most of the internet.
Which has nothing to do with what's discussed in the video but is driven in large part by the fragmentation of the IPv4 address space because of address shortage.
This was excellent, ty. He's not a natural talker, but fuck me does he love what he does.
it was sad at the end when the red frog had to leave the green one due to commitments with family at home....
on the plus side they will be able to keep in touch over the internet once someone finds out how BGP works..
I really enjoyed the higher level explanation
+FTWSkillDrain I really enjoy your sarcasm.
+Adi Serghei Who is being sarcastic? It was a qualitative explanation, but anyone with a basic math background can understand it in a deep way. If you can understand what he said you can take it to other context. If you want you can take basic linear algebra and apply it to any network.
+Adi Serghei it was a great video, I enjoyed it. Should have been accompanied with some more Numberphile videos though. And maybe splitting the subject into more videos.
that thing in the background make me feel like I need glasses
I have glasses and it made me take them off.
I have my algorithms final exam today so this is perfect! What a coincidence!
Still not sure what (semi) rings are / why they are called that
This seemed a bit to advanced for a 16min Video. Touching on so many subjects that none of them are clear to people without prioir knowledge.
Very interesting.... but I'm not sure I've learned anything.
+goeiecool9999 A gree, BGP was never actually explained, that's what I came here for. Instead he explained algebra I already knew and basic SP algorithms :|
see my comment above ....
perhaps we (meaning you Computerphile) need to redo this video... may have to mix around the order of explanations, add some diagrams etc...
Who’s here after Facebook’s BGP fail ?
I am here for the live lesson.
:D
I am but I still don't understand why the neighbor cannot trust the higher bandwidth path.
Everyone
Noone.
I think the title was a bit misleading on this one. Or I completely missed him BGP. I think something more general such as the problems with internet routing would be more appropriate.
Glad I found this video, very good overview of BGP and related network topics
Should be titled "Part 1", since we haven't even *gotten* to any of the meat (or even skin!) of BGP yet.
BTW, official ISP network administrator here! I'm the guy who has to adjust the weights if/when things congest, but of course the *real* meat of my job is to adjust/upgrade/supplement the *links* and/or re-engineer the routing graph well in advance of real bandwidth demand mustering up enough oomph to congest them. xD
see my comment above ...
My apologies Dr. Griffin, but I can't find any comments of yours above or below in this comment section aside from "see my comment above" written in reply to a few other folk as well? :o
-
Do you have a link you could share to said comment? :3
@@timothyggriffin where is it? : S
Oh my god, I love this guy, can we see more of him please!!!!
As an American, people chide me too when I say "root er" (router) or "roots" (routes). Makes more sense to me. People did not get their kicks on "Rowt" 66.
+rchandraonline In the context of networking, my preferred pronunciation is 'rowt' to avoid ambiguity with 'root' which has enough meanings in Unix already.
***** , most of the ones with which I have personal experience are "admin". But my sample size is really limited, like about 4.
Thank you so VERY MUCH for clarifying "routing" versus "rooting." I couldn't figure out what this new concept was. haha
Configuration of bgp is fun.
"Let me explain BGP" -> mildly interested
"So, semirings..." -> Oh, I know this! So they're finally doing some real computer science here! Go on!
"But we can't use them" -> So... I guess you will come back to them, right?
"bla bla bla" -> Uhm... Any more content, please?
outro -> Wtf just happened?
I often hear that "there is no centralized control over the Internet", but still there is some that can sell domain names, some that control the top domains, whatever I want to do on Internet it always end up in that I has to pay someone a huge amount of money. If no one controll it and no one owns it, where do the money goes and what shall I do if I want to become a ISP?
Thank you for a great channel and interesting videos.
+Jim Engström Run some cables down between your neighboring cities/countries and purchase some expensive routing equipment and then you will get 'free' internet... sadly you can only communicate with those on your network though. But you might be able to pay another ISP to forward your traffic the 'last mile' to their customers.
Notice he intersperses the UK pronunciation "rooter" (router) with the US pronunciation of "rowte" but not "root" (route)
more networking videos!
I hadn't thought of Dijkstra's algorithm as the source of defining a semiring on paths in a directed weighted graph (does summing edge weights and min'ing totals really form a semiring for any set of edge weights in a given graph? Any set of numbers?) Conversely, it makes sense that alternative strategies like that of optimizing for capacity might not behave the same. Indeed max of the mins of edge weights is not necessarily the min of maxes.
But what does any of this have to do with BGP and other protocols?
So, this process of picking the Min capacity link to represent a path and then compare it with another path using Max function, what is it called??
Very interesting as always 👍
Someone correct me if i'm wrong here, but wouldn't getting min bandwidth from each path and breaking on shortest distance resolve the distributivity issue? in the example given, both clients would choose the high bandwidth path, as the bottleneck was higher bandwidth than the other hop on the shorter path. I think this checks out in other scenarios too... but if so is probably obvious and i should just read up on semi rings in shortest path algorithms.
why those frogs got to be so cute
YES, NETWORKING. Too bad I already took my BGP exam before this video came out :x Still awesome vid.
This one is highly technical which kinda is a shame.
+Batsup1989 Just poorly explained.
+Mladen Mijatov Only partly his fault, that topic (in this depth) is just way to large and abstract for such short a video. Thats semesters of computer science for people without previous knowledge.
Ae Norist you are right, but I can't help but feel it could have been presented in a better way even at the cost of being too abstract.
Granted subject is a complex one and if nothing else he should have given enough knowledge to spark an interest for further research.
+Batsup1989 honestly I think it's a good thing, this channel is often rather dumbed down.
Beg to differ. It usually ranges from simplistic to very easily explained complexity (imho), which is why it might reach the audience it does, which is a good thing.
Not the best video....
Not even sure if it counts as a Parker Square.
as a professional network engineer I'm missing a sentence on distance vector vs. link state protocols.
I'd appreciate subtitles being added to these videos
Facebook.
Very interesting but the title seems not to fit content.... Need a part 2 to address bgp more.
Starts the video saying "rooting", changes it up to "routing" by the 13th minute... now my head hurts.
wtf is the backdrop?
A semiring
One thing I took away from this is that it could be beneficial to general population to break up commercial ISPs/their networks and transfer control to the (international) public (e.g. creating a "Euronet" in the EU). Am I missing some relevant info that makes this a bad idea?
yeah, but it's not a technical problem... you're advocating government takeover of the internet, what's wrong with you?
Still looking for the actual content in this video
Really interesting, thanks a ton!
I understood that but only because I have already done 3rd year networks at St Andrews.
Wonderful sir
I really thought wtf is he on about with his abstract operators then he said like yeah max and min and I was like ooooooh like that! Makes sense to use minimal values along a patht to determine the best path. A path is only as fast as it slowest link anyway.
probably the worst explanation of routing protocols I have ever heard. homeboy obviously never picked up a Cisco in his life. yes, least cost routing works on BGP to.
Does a router route or a rooter route or a rooter root?
His backdrop didn't fully cover all those Cisco Press books sitting on his bookshelf =)
I liked the bit with the frogs.
Is it sad that I have *EVERY SINGLE ONE* of those books on his shelf?
+tcpnetworks no it's cool (unlike the protocol your username references lol)
I am still waiting for an explanation of what a ring is, so I can know what a semi ring is, so I can understand the rest of this video.
more of this guy please. He explains all this very well!
Does anybody else feels like the video didn't really explain the BGP?
I just hope he's not a teacher..........
+Ang Ma
That's honestly what I think about a lot of people on this channel :/
He taught one of my lecture courses last year.
Will Shackleton So is he better if he has more time?
+Penny Lane he's a well noted academic but I've found that shows no correlation with teaching quality. He taught our courses on databases, and compiler construction, but neither of those seem to be his main area of expertise (networking and all that).
+Ang Ma He's certainly better at explaining things than some lecturers I've had, though I admit that I'm quite familiar with this subject area so I didn't find it too hard to keep up. He is trying to explain a lot of concepts for a fifteen-minute video, though, so I don't really think it's fair.
It is a bit odd, the whole thing of having researchers giving lectures. They're not necessarily skilled at imparting knowledge in spoken form, and a lot of them would probably much rather be getting on with research.
So it puts the "Inter" in "Internet" from "Internetwork".
wow, that background gives me a headache as I try to focus on it...
How many people believe this was tied to the FB hearings⚓
That's how the perfect english sounds like.
I think he just likes saying Dijkstra. It's not like we don't get what an algorithm is by the third time you've said it, bruh.
I wonder what they were hiding behind that greenish/blueish screenie-thingie there...
Distractions
Behind the colorful thingie is a diagram that explains BGP in a clear and concise way.
A Wizard of Oz controlling the Internet Machine.
it only took me 16 minutes from not understanding BGP to not understanding computer networks
For me one of the most informative videos I've ever had the honor to enjoy - really! Thanks a thousand times!
I know some of these words
should have done this with mpls
This video is pretty... oof.... I'd love to hear more about this topic. Can we ask a different guy?
I like the part when he said interface.
That background is really distracting
it just works
As cool as this video is they really should change the title 😂
They can't control the entire internet... but they sure are trying their darnest.
split pronunciation of 'routing', always fount that weird.
He's around the Brits too much.
But BGP won't let me be
So everybody just follow me
Cuz I'm the shortest path to your ISP
So everyone learn BGP!
Dan an an ar na, Dan an an ar na, Dan an an ar na, na na na na!
(To the tune of Slim Shady Woithout Me!)
Interesting accent. Reminds me of Kevin Spacey impersonating Jack Lemon.
"rooting" ... teehee :)
I understood the Kylie & Jason neighbours reference because I am Australian. :|
Misleading title. I did not learn about BGP after listening to him for 16 minutes. The title should change to " How to make a long speech in any topic!"
i like those frogs
Very good video, but I guess it should be in a place like Numberphile2-equivalent of Computerphile. Many people didn't understand and are complaining about the professor, who did a great job in my opinion.
Not a great video. Try it again.
Its route, not route
ahh yes.. the _rooting_ protocols
You cannot be serious.