Help describing this network situation

abcsunday

this is my problem/question
what is it called when two computers transmit at the same time along a network

i have no idea how to answer this question

thanks guys

Jon_Cisco

Is there any context to this question? My first though is it creates a collision but that is not necessarily the answer to your question. Is this referring to a single network segment. On a network lots of computers are always talking. Is there a term for it I don't really know. I'm not trying to answer your question for you just give you something to think about. Good Luck!

cyberguypr

Homework? I'm assuming you are talking about CSMA/CD. I hate to be that guy but I can't believe you didn't Google this. Just did it and saw the answer with everything from simple to extremely thorough explanations.

abcsunday

thanks for help for the tips i will double check on google

abcsunday

i was thinking about "Full Duplex" or "collision" not sure.. are they the same ? i m really confused

cwshellhamer

When two hosts "talk" at the same time on the same CD (collision domain) it causes a collision on the switch/hub. After the collision occurs they both wait a random amount of time and try to re-transmit until the frame is sent successfully.

remember switches & hubs are collision domains
routers are broadcast domains because they prevent collisions from happening. How? Wish i could tell you lol

Disgruntled3lf

REMOVED UNNECESSARY QUOTED REPLY FROM PREVIOUS POST Close but incorrect. Every device plugged into a hub is part of one big collision domain because a hub sends every packet out every port, less the one it came in on. Each port of a switch is a collision domain because a switch will look at it's internal table and only forward a packet out the port that is associated with the destination mac address. Every device on a switch is on a single broadcast domain. IE if I had a 24 port swithch with 24 devices I would have 24 collision domains and one broadcast domain. If I had two switches like above and connected them together directly I would have 48 collision domains and 1 broadcast domain. However, if I put a router between them I would have 48 collision domains (24 per switch) and 2 broadcast domains. As Jeremy Cioara says, " a router has 2 purposes in life. To route traffic and stop broadcasts." Edit: Felt like a jerk not ansering the OQ. I would say in that context (N+) it would be a collision.

markulous

@=cwshellhamer

Just to clarify here...Hubs are a single collision domain whereas a switch has a collision domain on each port. It's one reason why you never want to use a hub on a network.

Also, while a router does have separate collision domains on each port, you use routers to separate broadcast domains and switches to add additional collision domains.

cwshellhamer

@Disgruntled3lf

you had to cut that out of the book lol. Thanks for correcting/clarifying

abcsunday

@Disgruntledelf

thanks so much to explain this for me . from this way its so easy to understand what is collision domain

again thanks so much