Explanation of direct topologies? Serial - Serial...

[reyna12]

Need to know about 2 direct topologies, usb to usb and serial to serial, what they are.

Was for a bit of work due in Wednesday, Any help would be well appreciated

[MaxP]

Hmmmmmm....

having been in the trade fo ten years odd i cannot recall any sort of topology being used in referance to USB or Serial...

i recall the term "direct topology" being used in referance to network design...

can you clarify the question...

[Sanj[UK]]

i would of thought of it as a direct connection :/

[reyna12]

Hmmm what would you explain it as in reference to network design?

Thanks Appreciated

[MaxP]

Hmmm what would you explain it as in reference to network design?

Thanks Appreciated

inrelation to a network design the two terms are....

In-Direct Network Topology
this would be you normal network lay out with a master switch at the top which in turns feeds down to lower level switchs...
just the same as you would have a single Boss who then leads to several dept managers who then leads to the many minions.
in this situation the switchs at the lowest level do not have any direct connection to other switchs at the same level.
instead any data would have to be passed up the hieacrchy and then back down again.

the problem with this set up is that if a major switch was to die then you would effectly cut off all the switchs that reply upon it to speak with the rest of the network.

Direct Network Topology...
this refers to a design where each switch had a direct (cabled connection or backplate affair.) to each other switch. sounds daft i know but i have actualy seen it in practice.
a company i used to work for installed a brand new network using HP Procurve chassies with modual cards..(8 x 100mb ports per card..upto 10 cards per chassie or around that number)
the chap setting it up created a trunked pair between each switch (chassie) and every other switch (chassie).

the supposed benifit is that if any one single switch (chassie) was to die then the rest of the network would continue to operate just fine.
in practice its a load of old fanny...
befor the company had even started to use the new network they had already lost 18 ports per switch (2 ports used as a truck to every other switch of which there was 9...)
so with a switch which has 80 ports you had already lost 18...
a drop in capactiy of approx 22% befor you had even started.

the mind boggles as the procurve chassis had the abilty to use a gigabit backplate which would have connected all the swithces together at a greater speed with no lose to capacity and achived the very same result...

hope thats of some help.

[IAmATeaf]

USB is a daisy chained topology isn't it except where you put in a USB hub where it becomes a star, can't remember. Whereas serial is direct or point to point or if they're talking about old mainframes connected via dumb terminals then serial was used in a star fashion with a central connection hub.

[Gazzy]

Well it's a massive can of worms really, bearing in mind what people would define a 'topology' to be, and with reference with what particular technologies - network, connectivity, etc. I think the bulk of the answer has already been answered, but I just wanted to set the record straight on one particular thing.

In terms of network design, the term topology can either mean how a network is physical laid out (physical topology), or how the data travels across the medium (logical topology). This sub-categorising makes the whole thing simple really. 4 nodes connected to an ordinary Ethernet hub (CAT5/RJ45 style) is a star network physically, yet a bus network on a logical topology level - since all nodes share a common bus 'within' the hub. There's also wierd hybrids like token ring networks operating over a physical Ethernet (bus) network too.

Thought this might help for future reference.