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* Introduction [1]
* Logical view of different nodes: [2]
* ClientNodes [3]
* DxNode [4]
* CxNode [5]
* BxNode [6]
* AxNode [7]
* Variations [8]
* BxCx Hybrid [9]
* Re-trans [10]
* Hypothetical example [11]
* Link types [12]
* Node Examples [13]
* RGInnerNorth [14]
* Southern [15]
* Dandenong Foothills [16]
* Implementation of a Node [17]
INTRODUCTION
While the wireless network in Melbourne is in it's infancy other
communities have very well developed infrastructure. In the US
community networks are not nescessary providing an alternative network
to the ISP provided ones but are rather providing wireless access for
community members whereever they are.These networks are successful as
there is no bandwidth limits from the regular ISP's and every coffe
shop is able to hook up a DSL modem and an AP to become a node.
In the well developed "geek" centres (Bay Area, Seattle, Austin among
others) the local wireless orgs assist the setup of nodes to enlarge
the coverage of the network. That's not to say they don't build
backbone infrastructure as it is also high on their objectives but
citywide access for members seems to be the driving factor.
Here in AUS it's a little different as the lack of competition means
that most ISP's still gouge their customers and aply fairly draconian
conditions (about what you can hook up, sharing your bandwidth, etc.).
The Melbourne Wireless network is pretty fragmented at the moment.
There are pools of linked nodes but no city wide backbone yet. That
seems to be the primary goal for the group at the moment. Creating a
backbone is very dependant on individuals that want ot be part of it.
So what is a node and do you have one yet?
Seattle Wireless probably has the best classification of node types:
* ClientNode [18]
* DxNode [19]
* CxNode [20]
* BxNode [21]
* AxNode [22] (or Super BxNode [23])
These node definitons really need to be applied a bit loosely as in
reality a node will start out as one type and morph into a different
type depending on the availability of other nodes to link to. Perhaps
the most common variation would be a hybrid BxCx [24] that would have
links to other nodes and support either ClientNodes [25] or CxNodes
[26] on the BSS interface.
Another common evolution would be a node that starts out running a
BSS interface and has a number of other nodes pointng their uplink
links to it. In this case the links may be sub-optimal but are likely
to suffice for the ammount of traffic and usage of the connected
nodes. (Note that as the discrete areas of connectivity coalesce and
the network becomes used more that these types of "shared" connections
will become bottlnecks in the network).
LOGICAL VIEW OF DIFFERENT NODES:
CLIENTNODES
A ClientNode [27] is a node that connects to a DxNode [28] or CxNode
[29], typically using BSS mode. It could be a PC, laptop or handheld
device. A ClientNode [30] could be fixed or mobile.
DXNODE
DxNodes [31] is a node without any upstream connection, this is
typically the node you install at home when you want to get wireless
in your house. It allows your wireless devices to be part of your home
LAN and you may have internet access for your own personal use. In
this scenario you keep the node closed and may use some form of
encryption (weak though it may be).
+-----------------+ | | | | | +-----+ | | BSS |---/--- to
ClientNodes [32] | +-----+ | | | | +-----------------+
CXNODE
CxNode [33] is a node with one upstream connection. A CxNode [34]
connects to a single BxNode [35]. The CxNode [36] accepts connections
from ClientNodes [37] and routes thouse requests to it's upstream
connection. At this level routing is easy. The CxNode [38] is the
on-ramp to the local wireless network.
+-----------------+ | | | | | +------+ | | BSS | ---/--- to
ClientNodes [39] | +------+ | | | +------+ | | IBSS | +++++++++ to
upstream BxNode [40] | +------+ | | | | +-----------------+
BXNODE
BxNodes [41] support a pool of CxNodes [42] and have two links to
other BxNodes [43] provides DHCP to the client CxNodes [44] and
intellegent routing. So a BxNode [45] has 3 radios, one for supporting
the CxNode [46] pool and two more for making redundant links to the
rest of the backbone using two other BxNodes [47].
+-----------------+ | | | | | +------+ | | BSS | ---/--- to CxNodes
[48] | +------+ | | | +------+ | | IBSS | +++++++++ to peer BxNode
[49] | +------+ | | | +------+ | | IBSS | +++++++++ to peer BxNode
[50] | +------+ | | | | +-----------------+
AXNODE
AxNodes [51] or Super BxNodes [52] have more then 3 radios and tend
not to support a client cloud ( no CxNodes [53] hanging of it). It
provides routing between it's multiple interfaces.
VARIATIONS
A number of variations of this classification exist. Perhaps the most
common are nodes that provide a hybrid functionality betwen a CxNode
[54] and a BXNode. This is common in a young network such as ours as
it is more important to get some links in place than to do it in a
strictlu herachical sense.
BXCX HYBRID
A node that could qualify as a BXNode is more of well linked CxNode
[55]. This node has the typical CientNodes [56] but also has a link
(or two) to other BxNodes [57] on the same interface. The ideal
situation would be for this node to have a dedicated raido(s) for the
links to the BxNodes [58] but for the time being the conncetion is
established using the omni interface of the node.
RE-TRANS
A re-trans is a pair of radios that provide linkage between two nodes
that would not otherwise be able to connect. A retrans may be
desirable due to terrain and the lack of suitable nodes in the
location.
HYPOTHETICAL EXAMPLE
In this example a number of BxNodes [59] are configured in the same
manner. They use Ch 6 in IBBS mode to communicate to one or more
CxNodes [60] that in turn use Ch12 in BSS mode to commuicate with a
number of ClientNodes [61]. This is kind of an ideal situation, each
BxNode [62] has 3 radios with dedicated links. In reality many of our
Nodes will be less optimal.
| +-----+IBBS +------+ | BxN [63] |---/--- -->|Client| +-----+Ch 6 /
+------+ IBBS|Ch 1 / +-----+IBSS +-----+BSS / +------+ | BxN [64]
|---/--->| CxN [65] |---/--->|Client| +-----+Ch 6 +-----+Ch12 +------+
| | +------+ This client could roam between the IBBS|Ch 11 -->|Client|
the two CxN [66] if they used the same ESSID | / +------+ | /
+-----+IBSS +-----+BSS / +------+ | BxN [67] |---/--->| CxN [68]
|---/--->|Client| +-----+Ch 6 +-----+Ch 1 +------+ IBBS|Ch 1
+-----+IBBS +------+ | BxN [69] |---/--- -->|Client| +-----+ +------+
|
LINK TYPES
It is possible to create a link in different ways, the commonest ways
are supported in most wireless devices (cards and APs). The simplest
links are those that use BSS mode where an AP is the hub for all
transmissions. This is fine for the DxNode [70] you use in the house
and for connecting ClientNodes [71] to a CxNode [72] but has some
limitations when trying to use it for backbone links (the major one
being that all traffic is routed through the AP)
In the backbone it is useful to build redundancy through multiple
connections. Some of thes connections are achieved with multiple
physical radios but as the density of nodes increases it is possible
that multiple nodes can provide alternative routes for traffic.
Not all links are equal. The typs of link are discussed here in
increasing order of preference.
* BSS
* WDS
* Bridge
* IBBS
>
NODE EXAMPLES
Looking at the node finder we can see that there is not a lot of
linkage activity in our network yet. Some areas are well on the way to
creating isolated BxNodes [73] that serve potential CxNodes [74] but
we don't have much in the way of BxNode [75] linkage.
RGINNERNORTH
NodeBHH [76] is a great example of an almost-BxNode. There are lots
of links sharing the same radio and some of these links are potential
BxNodes [77]. This is an example of growing and changing as needed. If
one of the linked sites establishes a further link to another
potential BxNode [78] then BHH may drops it from the BSS connection
and establshes a dedicated link (or perhaps not!).
BSS|Ch 6 | +-----+BSS >| FUS |---/--- Bx----+Ch 3 +-----+BSS
+-----+BSS | BHH |---/--- >| FZJ |---/--- +-----+Ch 11 Cx----+Ch 3
+-----+BSS >| FMK |---/--- Cx----+Ch 8 +-----+? >| FNZ |---/---
Cx----+Ch ? +-----+ >| DCH | (ClientNode or DxNode [79]) +-----+
+-----+ >| HFL | (ClientNode?) +-----+
* NodeFZJ [80] is a CxNode [81]. It has a p2p link back to BHH and
has an omni for client connections.
* NodeFNZ [82] is another CxNode [83] with the backlink to NodeBHH
[84]
* NodeDCH [85] looks like it has only one interface as either the
backlink to NodeBHH [86] (ClientNode). or acting as a DxNode [87] in
omni role.
* NodeHFL [88] looks like it has the backlink only, so is a
ClientNode [89].
* NodeFMK [90] is a CxNode [91] with the uplink to NodeBHH [92].
* NodeFUS [93] is another BxNode [94] in waiting. It has 3 radios,
on connected p2p to BHH, another p2p (presumably waiting for someone
to connect it to - how about GPR?) and an omni for CxNode [95] or
client connections.
SOUTHERN
So whats going on here? NodeGMR [96] and NodeGES [97] are BxNodes
[98] and AFH and FBD are on their way to being the same. Again the use
of BSS and linking into the omni of a neighboring node seems to be the
norm, the BxCx [99] hybrid we saw in the other example.
+-----+ | HZN | +-----+ | | IBSS|Ch ? IBSS|Ch 2 | | +-----+BSS
+-----+BSS +-----+BSS +-----+BSS | GMR |---/--- >| GES |---/--- >| AFH
|---/--- >| FBD |---/--- Bx----+Ch 4 Bx----+Ch 1 Cx----+Ch 4 Cx----+Ch
1 | BSS|Ch ? | +-----+ >| GEZ | +-----+
DANDENONG FOOTHILLS
Classic BxNode [100] structure here.
BSS|Ch ? | +-----+BSS +-----+BSS +-----+BSS | AAF |---/--- >| GUR
|---/--- >| HKF |---/--- Cx----+Ch ? Bx----+Ch 8 Cx----+Ch 6 | |
+-----+ +-----+ | >| FGH | >| HUT | | +-----+ +-----+ | | +-----+
+-----+ | >| FUT | >| ICW | IBSS|Ch 6 +-----+ +-----+ | | +-----+
+-----+ | >| HCL | >| HNB | | +-----+ +-----+ | | +-----+ | >| GAZ | |
+-----+ | +-----+BSS +-----+BSS +-----+BSS +-----+ | FKR |---/--- >|
HKR |---/--- >| GWS |---/--- >| BFI | Bx----+Ch 1 Cx----+Ch 10
Bx----+Ch 11 +-----+ | | BSS|Ch ? +-----+ BSS|Ch 1 | >| HLR | |
+-----+
+-----+ >| HMF | +-----+
+-----+ >| FRJ | +-----+
IMPLEMENTATION OF A NODE
There are a number of ways to implement a node (regardless of type).
Reagrdless of implemetation they fulfill the same basic function,
provide a number of interfaces, provide intelegent routing between
interfaces and offer additional services.
Links:
------
[1] http://melbournewireless.org.au/#introduction
[2] http://melbournewireless.org.au/#logical_view_of_different_nodes_
[3] http://melbournewireless.org.au/#clientnodes
[4] http://melbournewireless.org.au/#dxnode
[5] http://melbournewireless.org.au/#cxnode
[6] http://melbournewireless.org.au/#bxnode
[7] http://melbournewireless.org.au/#axnode
[8] http://melbournewireless.org.au/#variations
[9] http://melbournewireless.org.au/#bxcx_hybrid
[10] http://melbournewireless.org.au/#re_trans
[11] http://melbournewireless.org.au/#hypothetical_example
[12] http://melbournewireless.org.au/#link_types
[13] http://melbournewireless.org.au/#node_examples
[14] http://melbournewireless.org.au/#rginnernorth
[15] http://melbournewireless.org.au/#southern
[16] http://melbournewireless.org.au/#dandenong_foothills
[17] http://melbournewireless.org.au/#implementation_of_a_node
[18] http://melbournewireless.org.au/?ClientNode
[19] http://melbournewireless.org.au/?DxNode
[20] http://melbournewireless.org.au/?CxNode
[21] http://melbournewireless.org.au/?BxNode
[22] http://melbournewireless.org.au/?AxNode
[23] http://melbournewireless.org.au/?BxNode
[24] http://melbournewireless.org.au/?BxCx
[25] http://melbournewireless.org.au/?ClientNodes
[26] http://melbournewireless.org.au/?CxNodes
[27] http://melbournewireless.org.au/?ClientNode
[28] http://melbournewireless.org.au/?DxNode
[29] http://melbournewireless.org.au/?CxNode
[30] http://melbournewireless.org.au/?ClientNode
[31] http://melbournewireless.org.au/?DxNodes
[32] http://melbournewireless.org.au/?ClientNodes
[33] http://melbournewireless.org.au/?CxNode
[34] http://melbournewireless.org.au/?CxNode
[35] http://melbournewireless.org.au/?BxNode
[36] http://melbournewireless.org.au/?CxNode
[37] http://melbournewireless.org.au/?ClientNodes
[38] http://melbournewireless.org.au/?CxNode
[39] http://melbournewireless.org.au/?ClientNodes
[40] http://melbournewireless.org.au/?BxNode
[41] http://melbournewireless.org.au/?BxNodes
[42] http://melbournewireless.org.au/?CxNodes
[43] http://melbournewireless.org.au/?BxNodes
[44] http://melbournewireless.org.au/?CxNodes
[45] http://melbournewireless.org.au/?BxNode
[46] http://melbournewireless.org.au/?CxNode
[47] http://melbournewireless.org.au/?BxNodes
[48] http://melbournewireless.org.au/?CxNodes
[49] http://melbournewireless.org.au/?BxNode
[50] http://melbournewireless.org.au/?BxNode
[51] http://melbournewireless.org.au/?AxNodes
[52] http://melbournewireless.org.au/?BxNodes
[53] http://melbournewireless.org.au/?CxNodes
[54] http://melbournewireless.org.au/?CxNode
[55] http://melbournewireless.org.au/?CxNode
[56] http://melbournewireless.org.au/?CientNodes
[57] http://melbournewireless.org.au/?BxNodes
[58] http://melbournewireless.org.au/?BxNodes
[59] http://melbournewireless.org.au/?BxNodes
[60] http://melbournewireless.org.au/?CxNodes
[61] http://melbournewireless.org.au/?ClientNodes
[62] http://melbournewireless.org.au/?BxNode
[63] http://melbournewireless.org.au/?BxN
[64] http://melbournewireless.org.au/?BxN
[65] http://melbournewireless.org.au/?CxN
[66] http://melbournewireless.org.au/?CxN
[67] http://melbournewireless.org.au/?BxN
[68] http://melbournewireless.org.au/?CxN
[69] http://melbournewireless.org.au/?BxN
[70] http://melbournewireless.org.au/?DxNode
[71] http://melbournewireless.org.au/?ClientNodes
[72] http://melbournewireless.org.au/?CxNode
[73] http://melbournewireless.org.au/?BxNodes
[74] http://melbournewireless.org.au/?CxNodes
[75] http://melbournewireless.org.au/?BxNode
[76] http://melbournewireless.org.au/?NodeBHH
[77] http://melbournewireless.org.au/?BxNodes
[78] http://melbournewireless.org.au/?BxNode
[79] http://melbournewireless.org.au/?DxNode
[80] http://melbournewireless.org.au/?NodeFZJ
[81] http://melbournewireless.org.au/?CxNode
[82] http://melbournewireless.org.au/?NodeFNZ
[83] http://melbournewireless.org.au/?CxNode
[84] http://melbournewireless.org.au/?NodeBHH
[85] http://melbournewireless.org.au/?NodeDCH
[86] http://melbournewireless.org.au/?NodeBHH
[87] http://melbournewireless.org.au/?DxNode
[88] http://melbournewireless.org.au/?NodeHFL
[89] http://melbournewireless.org.au/?ClientNode
[90] http://melbournewireless.org.au/?NodeFMK
[91] http://melbournewireless.org.au/?CxNode
[92] http://melbournewireless.org.au/?NodeBHH
[93] http://melbournewireless.org.au/?NodeFUS
[94] http://melbournewireless.org.au/?BxNode
[95] http://melbournewireless.org.au/?CxNode
[96] http://melbournewireless.org.au/?NodeGMR
[97] http://melbournewireless.org.au/?NodeGES
[98] http://melbournewireless.org.au/?BxNodes
[99] http://melbournewireless.org.au/?BxCx
[100] http://melbournewireless.org.au/?BxNode
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