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New Member

How's 2Mbps sufficient for 100Mbps

I know i may sound stupid but still.... How is a leased line of 2 Mbps sufficient for an ethernet connection of 100 Mbps, which is behind it? I mean, how come data coming from an ethernet connection of 100Mbps is able to go out through a leased line of only 2Mbps. Even, if the link is getting used to mere 10% of its capacity i.e 10Mbps, how's 2Mbps link sufficient for it?

5 REPLIES
New Member

Re: How's 2Mbps sufficient for 100Mbps

I believe what you are refering to is a bottleneck. Yes, even at only 2% utilization, the 100meg interface will overload the leased line interface. The 2 meg pipe might be sufficient depending on the number of users behind the PIX, and applications you will use. The PIX will support a larger outside interfaces if you need it.

Re: How's 2Mbps sufficient for 100Mbps

hi

Thats where you face congestion whichs the data flowing from high speed interface 100Mbps to a low speed interface which 2Mbps here in this scenario.

The only solution available out here is to use the congestion avoidance mechanism and congestion management mechanism.

Congestion avoidance relates to RED,WRED and the normal tail dropping techniques where in your congestion management involved WFQ,CBWFQ etc..

For more info on them would suggest this link ...

http://www.cisco.com/en/US/partner/products/sw/iosswrel/ps1835/products_configuration_guide_chapter09186a00800dc04c.html

regds

New Member

Re: How's 2Mbps sufficient for 100Mbps

Hi,

I've read the other responses, but had the feeling that this is a more general question that you're asking.

A kind of answer is that, how much of that 100Mbps do you actually want to go over the leased line: not a lot - most of the LAN traffic will be local, sent between hosts on the LAN & not sent over the WAN connection. If this isn't the case then either the LAN design needs to be improved or you'd need to assess what your WAN bandwidth requirements are.

The answer to your question then would be in the LAN/WAN design.

Apologies if I've misunderstood the meaning of the question.

New Member

Re: How's 2Mbps sufficient for 100Mbps

Thanks a lot, and yes, you got exactly what i meant. But is it related to a rule called 80/20 (i am not very sure what this rule is)

Re: How's 2Mbps sufficient for 100Mbps

The typical 80/20 rules is simply that on average 80% of your traffic will be local LAN and 20% will be WAN (Internet, connection to other site). This is just a rule of thumb and can vary greatly. Anything from all of the servers at one site to a company who downloads streaming media would be far off the mark from this rule but it is a good starting point. Your 2Mbps leased line may be fine for that site if the only thing running over it is your Internet.

Hope this helps

please remember to rate all replies

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