Switch speed comparing pps and Mbps

E

EinsteiN

Limp Gawd
Joined
May 9, 2000
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I googled around abit, but seem unable to weed out all the shops that wanna compare their products.

I would like to know the formular for converting pps to Mbps or the other way around.

The reason is because I'm in charge of choosing the new switches for this network, and the different manufactures seems unable to agree on a measurement of speed(Linksys by far the worst).

Anyways, I looking into the 24-ports 10/100(no gigabit - not enough funds) unmanaged switches, the network has 60+ nodes(it's growing) so I should not be worried about a small MAC-adress cache(4000+)?

And have no idea what to choose (I'm leaning against the Allied Telesyn FS7024), but if anyone has better alternatives, or good tips speak up.

Thanks in advance guys :)
 
Good luck.

For MAC addresses, look at how big your network will be. If you really think you'll have 4000 nodes on the segment then maybe you should look for more. But seriously, do you really need a HUGE MAC-address cache?

For comparing switch fabric to ports and whatnot, look at teh throughput required for all ports at full duplex. For a 24 port 100Mbit switch, in theory you'll need 2.4Gbit of potential throughput capability. As for packets per second, good luck. That's more of a measure of the switch's "CPU" (for lack of a better term). How much traffic can it push through a port before it croaks, or in the case of a switch, buffers them and hopefully doesn't block ports because of it. This where you need to compare Store-and-forware and Cut-through switching products (Cisco also has a third method, which I forget what its called ATM). Not all switches are created equal.
 
EinsteiN said:
Anyways, I looking into the 24-ports 10/100... unmanaged switches, the network has 60+ nodes...? Thanks in advance guys :)
Click to expand...
3Com = When management isn't ready to invest into IT infrastructure
Cisco = When they are...
 
EinsteiN said:
I would like to know the formular for converting pps to Mbps or the other way around.
Click to expand...
That's not possible. Packets sizes very and thus would change the amount of throughput in Mbps.

For marketing purposes, the vendor will typicall use a SmartBits tester to determine the "sweet spot" that their hardware can handle. Also, depending on the "features" that are enabled durring the test, the performance numbers can be skewed. In addition to that, the vendor will publish the aggergate numbers for the device, not a particular port or feature.

A vendor may calim that it's product can switch packets at 65,000pps but they don't say that those are 64 byte packets and that the switch was doing L2 switching with no RMON. If the device were to be switching 1500 byte packets with RMON enabled, the Packets Per Second may drop to 6,500pps (example only) but they sure as hell aren't going to publish those numbers.

Don't be a pure numbers person when it comes to picking a vendor or product. 3COM may clain to have the fasted L3 switch but once you enable ACLs or RMON, the faster L3 switch may become the slowest POS. ;)

Anyway, it doesn't sound like you need to worry. I agree that "not all switches are created equal", but most of the 24 port 10/100Mbps unmanaged ethernet switches on the market today are going to perform about the same. Back in 1997, it was a different story....
 
Bobsutan:
The network will be growing but will not surpass 100 nodes within the next 2 years is my estimate (It's a small dormatory). The question was concerning whether or not I should focus on the MAC-adress size, which I now wont. :) (Hadn't had that class in CS yet - had that today)

j4zzee:
Any of those to vendors are outside our budgetlimit.

ipconfig /all:
Yeah I was concerned that pps wasn't an aples to aples comparision, quess I was a little naive there. :)

Learn alot everyday :)
 
while cisco is very nice and worth every penny if you have it. If you aren't going to be using most of the CISCO IOS manament features i like Hp procurve. a whole lot less money and vertiually the same specs.
 
another vote for the hp procurve range. all our layer 2 switches are procurve 2524's. we do have some 2650's too when 'u' space was tight. our layer 3 and above is all alcatel equipment. we do have some foundry serveriron stuff for web stuff though - thats excellent too!
 
Atomizer.

Holy shiznit. You run alcatel for your layer 3? Which model? We used to run a bunch of 6024 and 5250 in the core. It is rare that if i found another enterprise running alcatel. <-- IMHO JUNK

Currently swimming in cisco goodness.

But going back to the original post. If 24 10/100 ports are all you need, than any of the soho equipment should suffice (Netgear/dell, linksys) (in order of preference).

If you want to get a managed switch, but don't want to pay too much, try the refurb cisco's. You can get them with smartnet and save some money. (well, they will be more than the soho gear) www.networkhardware.com is a good resource.

HP procurve's are really nice too. I run a couple of those.
 
I think it's slightly odd that people think so highly of the
Cisco brand name, considering that just about every product
they sell was designed by a different company. Are competing
companies considered to be as good as Cisco retroactively, once
they've been bought out and their products rebadged as Cisco?
 
shieldforyoureyes said:
I think it's slightly odd that people think so highly of the
Cisco brand name, considering that just about every product
they sell was designed by a different company. Are competing
companies considered to be as good as Cisco retroactively, once
they've been bought out and their products rebadged as Cisco?
Click to expand...

That's what Cisco is good at. Taking one company's technology and adapting it to fit into Cisco's vision of what a network should be and then backing it up with TAC. I think Cisco TAC is a big part of what makes Cisco "Cisco". I haven't found another company who supports their product like Cisco does. Not in the hardware arena, or the software arena.
 
Boscoh said:
I think Cisco TAC is a big part of what makes Cisco "Cisco". I haven't found another company who supports their product like Cisco does. Not in the hardware arena, or the software arena.
Click to expand...

Agreed. There isn't a company on the market that can compete with Cisco for customer service and support. And its this stellar support that gets them the gravy deals and big budget purchases. Face it, they are the IBM of our generation.

I agree that its funny how Cisco buys other companies and absorbs their product lines in theirs, but that just the way this business works. Why bother building a product to compete with someone elses, especially if theirs is done right, when you can just buy them for a fraction of the cost and reap the benefits of their quality products. That's how the Catalyst and PIX lines came to be.
 
i've never used cisco equipment - though i am thinking of beginning the ccna program to get it on my cv/resume.

to be honest im not even sure what's so great about it. i'm sure their equipment has its problems just like any other vendor.

the alcatel stuff gave us some teething problems but they have been resolved now and the network is now stable from that perspective ... albeit the equipment that continues to let us down is our wireless (licensed and unlicensed) gear and our dsl services (we use dsl modems over 'cheap' twisted pairs from carriers).

we've got stuff from ibm, dell, compaq, microsoft, oracle, novell ... the list goes on. each and every one of them all has their little 'features'!

i guess thats what keeps us in our jobs!

the only solution that does exactly what it says on the tin ... everytime ... is our foundry serveriron stuff. that stuff is just brilliant!
 
EinsteiN said:
j4zzee: Any of those to vendors are outside our budgetlimit.
Click to expand...

A new unmanaged 24 port 10/100 3Com Baseline switch can be had for under $250. I think that is pretty cheap?
 
Hehe thanx j4zzee

guess i didn't look hard(no pun intended) enough, so I think I will take these since they have lifetime warranty :)
 
how are 3com's backplanes though....last time i looked they were no were near as good for the money as HP.
 
oakfan52 said:
how are 3com's backplanes though....last time i looked they were no were near as good for the money as HP.
Click to expand...

It depends on the type of unit you are purchasing.
 
not sure about other vendors but hp are also next day business replacement should the unit fail. i have had very very few fail on me but their customer service is excellent! :D

thumbs up for hp!
 
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