Tom,
How are the "big boys" doing it? Surely AT&T and others are transporting
more than 200Mbps across their 1GB fiber links.
Travis
Microserv
Tom DeReggi wrote:
Gigabit Ethernet, can pass 1 gbps when it uses greater than a 9600 MTU
frame.
But with a 1500MTU frame, it can barely pass 200 mbps.
The problem is that most Internet and subscriber traffic is using a
1500MTU or smaller frame.
So in theory, its would be just as efficient and fast to bond two 100
mbps fiber connections than it would to buy 1- 1GB fiber connection.
So the question is.... How do we most efficiently use 1GB fiber to get
the advantage of the full 1GB of capacity?
Do we need to use some sort of packet agreegation/stuffing technology?
Is GB etherner pointless for Internet transit backbones?
Is GB just good for high capacity Transports, recognizing that routers
will likely split traffic to different smaller bandwidth peers?
Is there a special router or router feature used to solve this problem?
Is that method available to Linux?
The reason I ask is several fold. In a network design where all
traffic flows to a single source (for example many 100mbps baclhauls
to remote areas to 1 central data center), it would be beneficial
because the cost of 1 big 1GB pipe could be shared to deliver capacity
to everything, better apt to handle peak traffic and get higher
oversubscription rates. However, if teh GB INternet pipe can not be
efficiently used, this method would be severally flawed. It might be
better to have multipel 100mvps transit connections spread out across
one's network, so there was a shorter path to transit, and the
network's bandwdith spread out amungst multiple 100mbps transit
connection, for better over all throughput. In other words, in a 10
city network, 1- 100mbps pipe in each of teh 10 cities would allow a
full combined 1 gbps of Internet transit, where as agregating 100mbps
from each city to one central source where their was a single 1GB
transit, would result in only a 200mbps throughput, assuming traffic
was delivered to it as a 1500 MTU.
Any feedback?
Take note that my comment that a 1500MTU frame 1 Gbps Ethernet card
could only pass 200kbps was based on some lab tests. With the 1500MTU
frame acheiving only 200kbps, our routers CPU utilization was less
than 20%, so it was not a saturated router. The second we changed MTU
to 9600, we got over 800 mbps, and CPU utilization was still very low,
forget exact number but under 40%. These tests were replicated going
PC to PC (no switch) and with a high end SMC GB switch in-line.
Tom DeReggi
RapidDSL & Wireless, Inc
IntAirNet- Fixed Wireless Broadband
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