Everyone take a deep breath before reading the thread. There is conflict ahead, but we knew that. Read it only if you're willing to take the view that what is written is done so under the best possible intentions. On 03/12/2013 03:04 PM, ZPO wrote:
Quick note before I get dragged back into work....
Bart is correct that MESH has been overloaded as both a name for a topology and a proper noun for a specific implementation of a MANET. As long as we know what we're talking about, we can use either term. We can call it MANET which is technically accurate, or MESH since that is commonly used and understood.
I'm glad we agree on at least that. :) Let's stick with MESH in all caps when referring to NW-MESH type stuff, since MANET can also mean a network like HamWAN and we'd once again be ambiguous.
I view the NW-MESH and HamWAN projects as complimentary. HamWAN in general and the PSDR component in particular makes an excellent backbone transport network to move data around the wider area. NW-MESH works well to cover the last mile.
This is where I think HamWAN is being sold short, since it also works great on the last mile. Reason being is HamWAN sites are all planned to be non-ground-level, so LoS probability increases which makes last mile happy. Your trip may be physically longer by a few miles, but the latency and speed will still be good, if not better when compared to multiple ground hops for the same distance. In close-proximity situations, the end-user-site to end-user-site direct connectivity of NW-MESH I believe provides an optimization. A COUPLE hops of MeSh might indeed be superior to traversing a busy sector.
Full bidirectional interconnection of the networks has some significant challenges as Bart states. They are surmountable, but there are some issues to address.
I'm glad we both recognize this fact.
On the other hand, using the PSDR as a transport means for interconnecting pockets of NW-MESH is not terribly difficult and can be done rather simply.
It sure can! But read on to the last point.
I greatly prefer to keep the projects separate and have a collaboration on the interface between the two efforts outside the mainline work of either. The projects have differing goals, differing timelines, and differing concepts.
And I'd greatly prefer to merge the projects, because I'm not convinced that we do have differing goals. If our goals can be communally stated as "provide the amateur radio community with a fast wide-area multi-megabit IP-based digital network that can scale and out-last either of us", then I think we have a chance at merging, because that's pretty much the HamWAN mission statement. For the more detailed version, see the official HamWAN mission statement <https://www.hamwan.org/t/tiki-index.php?page=Constitution&structure=HamWAN>, which is the first article of our constitution. This is where I think you, Rob, and the rest of the NW-MESH team need to get together with the HamWAN people to spell out exactly what it is that each of us is trying to accomplish. Do you have a mission statement you can share? Do you have a favorite low-noise public meeting location with power + wifi? Starbucks is sounding likely.
I'd like to see some more detail from Bart on what he sees as the large issues with bidirectional interconnection (I think I know most of them) or simply using the PSDR as transport via tunneling between access nodes.
So even though it's possible for HamWAN to act as a dumb pipe for NW-MESH, this is not a fair arrangement for HamWAN. If this were a peering agreement at an Internet exchange, it would be considered a violation of the terms of service set out in every Internet exchange I'm aware of. A fair peering agreement is where each network moves equal amounts of data to and from a peer, where said traffic is between clients of each network. This means not via a peer network, and the traffic is from/to clients of the same originating network. With BCWARN, it's easy. We each cover different regions, we each come to the game with our own backbone transport, so we are indeed peers and can exchange traffic as such with no ill feelings. BCWARN also uses OSPF/BGP and public IP addresses, which simplifies matters even more. They also have restrictions in place as to who can participate so we're not carrying questionable traffic on HamWAN. In short, all the bases are covered and we're happy to peer. I'd rather not spell out the NW-MESH incompatibilities with networks like BCWARN and HamWAN in this email, simply because I don't feel qualified. I'll need to ask questions in order to fully explore the subject. This is where I think it makes sense to have a meeting between our groups and hash these technical things out. Off the top of my head, the attributes of using 10/8 space is a problem since it can conflict with people's home networks (and other reasons), as is the access policy since as far as I know any non-ham can just get the key and join a NW-MESH node. Correct me if I'm wrong. Hell, I don't even know if NW-MESH is running part 97 or part 15 rules. What say you? :) --Bart
73-KY9K/Brian
On Tue, Mar 12, 2013 at 2:16 PM, Bart Kus <me@bartk.us> wrote:
Hi Craig,
First, let's speak the same language.
There's a lot of confusion around the word "MESH". I'm also not sure why it's always capitalized. It's not an acronym as far as I know. The term "mesh network" describes nothing more than the logical topology of a network. There's a really good write-up on this at the wikipedia page. I'm pretty sure that when you (and others on this email) use the phrase "mesh network" it is not the wikipedia definition you're intending. It means something different, including:
1) Using a common RF channel 2) Promiscuous neighbor discovery + association 3) Automatic IP configuration based on MAC 4) Nearly open node authentication 5) Omnidirectional operation 6) WDS-style operation
These are the typical traits of a SeattleWireless style mesh network (which, BTW, has been attempting to bootstrap itself for the last 13 years). This type of definition of "mesh network" is quite a different animal from the canonical mesh network definition (wikipedia's, derived from network theory).
The reason I want to make the distinction clear is that nearly all large networks in the world are indeed mesh networks, but nearly none of them possess the qualities of 1-6. So when I say something like "HamWAN is a mesh network", I want it to be clear that I'm referring to the network topology only (the wikipedia definition). I'm not sure what is the right word to describe the other type of network; perhaps capitalizing all the letters is a good differentiator after all. :)
So, with the definitions out of the way, let me address your actual email now that I can speak to it unambiguously.
I concur that we all want to implement a mesh network, but I don't think everyone wants to implement a MESH network. Phrasing the problem of "how do we provide modern digital communications to the ham community" in terms of "how do we implement a MESH network" is putting the cart before the horse. Over the last 6 months, I've been leading the HamWAN effort to create solutions to the first question. We've made respectable progress on both the RF engineering and networking fronts. We had a fully functional cell site setup @ last weekend's Flea Market. This site design is about to start rolling out to the real world.
This transition in the project's status has allowed me to start thinking about how HamWAN might integrate with other ham networking efforts. We've had a good relationship with BCWARN.net for the last few months, and integration with that network will be simple. The physical links are already planned in fact! We're both excited to make it happen and start exchanging traffic internationally!
The integration with NW-MESH efforts is far more challenging. In fact, it may be outright impossible unless changes are made in the NW-MESH design. From what I've seen, this difficulty of peering will be present in all MESH networks. The problems range from simple route exchange, to address space conflicts, to policy propagation (access, QoS, filtering, etc). I don't even wanna think about DNS. :P
Having said all that, there is some value to HamWAN using a MeSh (hybrid of mesh and MESH) layer. Traffic between nodes may flow more optimally on the ground than through the mountain sites. A nearby ham who doesn't want to invest in a dish might get on HamWAN by MeShing with his neighbor. I'd be good for the health of HamWAN to make use of these optimizations. But like I said, in order for these routing decision to be made correctly and automatically, NW-MESH designs will need to change.
I'd like to invite you (in fact, all of you) to join the HamWAN weekly meeting today @ 7PM. I'll re-send the connectivity details on the mailing list (email: psdr-join@hamwan.org) an hour before the meeting, but basically install Mumble 1.2.4+ (currently beta), and connect to BartK.us. Please use a headset to avoid generating echoes.
Craig, can you give me an idea of your skills? Perhaps you would enjoy solving these types of problems as part of the HamWAN development team? We run a tight ship with specific assignments and weekly reporting. I believe this is the "small group of experts" approach you were proposing. :)
--Bart
On 03/12/2013 12:09 PM, Craig B wrote:
When I first heard about the MESH project from Daniel Stevens (KL7WM) back in late fall 2012, the first question I had for him was "what will it connect to?" Since then, as I have become more involved I have started to formulate what I think it could be connected to and how it could be used.
Based on what I have learned and seen to date, I see 3 tiers of network involved here. The backbone, which I see as a long-haul that would be based on a region that is defined by terrain and distance. The middle tier would be smaller and could be between HAM towers or other "secondary" sites. The 3rd tier would be for the "neighborhood" or "home" MESHing with WRT's and other low-power devices. In this type of configuration, I see the backbone as being the one common piece across regions while the secondary and tertiary tiers could be specific to the 'regional' implementation. Each tier would have to bridge from itself to the next level, which seems to be reasonable where a given site could choose to bridge by adding necessary hardware or remain remote.
What I would like to do is see if we can't get a written network plan for a regional backbone and then any additional tiers that need to be included in a good network design document. I am a firm believer that it should be hardware agnostic for the most part, although could provide a list of acceptable components that have been shown or believe to be the best hardware based on application. It would also dictate how traffic might be handled moving up/down through the tiers, possibly allowing for QoS or other transport methods.
As I am sure we all want to see a MESH network available to all HAMs; given the area NW-MESH has been getting feedback on, I think we need to start looking at how we connect them all together. As such, in talking with Bob Rutherford, it seems like the first step is to build out a plan that could be presented to FWARC, Tukwila Radio Club, and EMCOMM (and other clubs/groups).
Since this is all great in theory, it seems the next step is to secure funding and move it from paper to reality. Given the real application of this MESH network for EMCOMM, and their generally deep pockets, it seems like a great way to get a backbone built.
If we are going to design this, I believe it needs to be initially designed by a small group of network and radio experts. Once an initial plan is cobbled together it could be released to the larger MESH community for comments and additions/subtractions, etc.
I am willing to take on leading this charge; however, I will need a team of experts behind me helping lay the ground work. My initial thought is to have something ready by mid or late summer, given that we all have other priorities as well, not adverse to taking longer if it means having a complete and well planned out design.
Any thoughts on this?
Thanks, Craig KF7LLA