I’ve worked in networking for about six years now. Not that much but I think I observed some key aspects of this world.
Think of slides and presentations about a new products or solutions. You will have the business slides, where you talk about use-cases and revenue generation, on one side and tech slides where you see how things work on the other.
What often happens is that those two worlds, business and tech, do not “touch” each other.
Most times, this makes sense. Let’s consider OSPF; it would be hard to have an executive manager “excited” about it or see ospf as a revenue generator. Ok, ospf allows connectivity so, at least for a service provider, connectivity, with the help of ospf, means revenue.
Anyhow, I understand ospf is not so appealing to be seen as a revenue enabler. The same goes with static routing, rsvp, mpls and many more.
At the end of the day, all those protocols are just network protocols that somehow support services.
That’s also because revenues are associated with services (not simple connectivity) to answer real-life needs.
Under this perspective this business-tech separation is legit… unless one case: BGP.
I’m not saying BGP is something business executives have to know but, among all the tech things, it is probably the one closest to the glue between the two worlds.
BGP really can be seen as the enable of all those revenue-making services.
Business people should not study or be BGP expert but they should be aware of its importance and keep that in mind when building their networks. Choosing a vendor with an excellent BGP implementation will translate in a higher chance to generate revenue.
Think of this typical service provider use-case: “My customer is a large company with many branches. It would like to connect all those branches by forcing all traffic to go through its HQ location and would also love this big network to be private”.
The business need is pretty clear and simple: connect locations so that they talk to each other speeding up business processes. The required service is to distribute routing information (branch addresses) so to build a hub and spoke topology and keep everything private (allowing other SP customers to use the same address blocks).
What’s the solution here? A Layer 3 VPN!
Layer 3 VPNs involves many tech concepts: vrfs, rsvp, ldp, lsps, mpls, bgp, igp…
Among them, who is the one that really makes a VPN possible? Yes…BGP!
How? Inside BGP packets we have 2 key fields: AFI and SAFI.
AFI represents the address family of the BGP advertisement, for example AFI 1 is IPv2 (complete list here https://www.iana.org/assignments/address-family-numbers/address-family-numbers.xhtml).
SAFI, instead, specifies the “nature” of the routing information included.
SAFI is key here. Check the complete list and you should understand why BGP is so important https://www.iana.org/assignments/safi-namespace/safi-namespace.xhtml .
Back to our business need! We told our service needs to advertise routes that can overlap among different SP customers and build a hub and spoke topology.
How does BGP achieve this?
- hub and spoke topology relies on extended BGP communities (route targets)
- route advertisement will use SAFI 4 (or 128)
Why those AFIs? Because, according to the standard, those are the SAFIs associated to NLRI with MPLS labels or MPLS-labeled VPN addresses.
SAFI 4/128 carry VPN routing information.
It is clear now… it is BGP that brings services! BGP is the service enabler. BGP is not just a routing protocol, BGP is a service protocol!
Now, think of other business use-cases.
Customer needs to connect two remote locations so that it seems there is a point to point link between them. The SP will probably sell a service called “Next to me” but, under the hoods, it will build a pseudowire and the service information are, once again, carried by a BGP advertisement using a specifc SAFI for L2VPN.
And what if we wanted to provide geographical LANs? BGP carrying service information used to build and maintain a VPLS or, better, EVPN (both have their SAFI).
The list is not over. Large enterprises might have multiple Data Centers and they might desire to interconnect them at L3 or L2. You might design a service, call it “One DC”, sell it and make revenues. Just know that service was provided using BGP carrying evpn information.
Is it just about connectivity use-cases? No!
Security has become a critical concern over the last few years (maybe not enough) and DDoS attacks take place every day. An SP could offer a service where malicious traffic is discarded or sent to a security appliance for further analysis. Guess what? BGP cna be the skeleton of this service once again by leveraging the FlowSpec functionality. Flow details are carried within BGP packets using a specific SAFI value.
We have seen how BGP can help delivering a wide variety of services.
But is carrying services information everything it does? Of course not.
Think about routing protocols. Link State vs Path based, convergence time, fault tolerance. Those are all aspects that become technically relevant when comparing or choosing a protocol.
With BGP, those aspects become crucial for the services it brings! A fast convergence time means a faster reaction in case of faults which translates in revenue protection as you will likely have less complaints from customers.
You see, BGP is not just a routing protocol. People might underestimate how such a protocol is important for business and how tight its relationship with business revenues is.
BGP is the perfect touch point between business/marketing and tech and both worlds should be aware of its relevance.
Captivating use-cases are important as they generate revenues but service providers should never forget what makes those revenues possible and, in most cases, BGP is one of the protagonists.
Choose a great BGP solution and you will be one step closer to higher revenues and cost reduction!
Ciao
IoSonoUmberto
IoSonoUnRouter 