Re: what is wire-speed?
Hi all, Any body knows what they mean by saying "wire-speed" forwarding about a switch? Also, when Cisco says a switch can forward at 100 million pps or something like this, what the size of the packets they usually refer to of the PPS(packet per second)? 64byte? Thanks Kent __ Do You Yahoo!? Yahoo! Mail - Free email you can access from anywhere! http://mail.yahoo.com/ **NOTE: New CCNA/CCDA List has been formed. For more information go to http://www.groupstudy.com/list/Associates.html _ UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html FAQ, list archives, and subscription info: http://www.groupstudy.com Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: what is wire-speed?
wire-speed meaning it's processed almost as fast as it comes through the wire unlike when bridging is done via software. "Kent" <[EMAIL PROTECTED]> wrote in message [EMAIL PROTECTED]">news:[EMAIL PROTECTED]... > Hi all, > > Any body knows what they mean by saying "wire-speed" > forwarding about a switch? > Also, when Cisco says a switch can forward at 100 > million pps or something like this, what the size of > the packets they usually refer to of the PPS(packet > per second)? 64byte? > > Thanks > > Kent > > > > > __ > Do You Yahoo!? > Yahoo! Mail - Free email you can access from anywhere! > http://mail.yahoo.com/ > > **NOTE: New CCNA/CCDA List has been formed. For more information go to > http://www.groupstudy.com/list/Associates.html > _ > UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html > FAQ, list archives, and subscription info: http://www.groupstudy.com > Report misconduct and Nondisclosure violations to [EMAIL PROTECTED] > **NOTE: New CCNA/CCDA List has been formed. For more information go to http://www.groupstudy.com/list/Associates.html _ UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html FAQ, list archives, and subscription info: http://www.groupstudy.com Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: what is wire-speed?
Yes the numbers are based upon 64 byte packets. All vendors do this for the numbers game. You gotta love marketing. "Kenneth Lorenzo" <[EMAIL PROTECTED]> wrote in message 8ph51t$413$[EMAIL PROTECTED]">news:8ph51t$413$[EMAIL PROTECTED]... > wire-speed meaning it's processed almost as fast as it comes through the > wire unlike when bridging is done via software. > > "Kent" <[EMAIL PROTECTED]> wrote in message > [EMAIL PROTECTED]">news:[EMAIL PROTECTED]... > > Hi all, > > > > Any body knows what they mean by saying "wire-speed" > > forwarding about a switch? > > Also, when Cisco says a switch can forward at 100 > > million pps or something like this, what the size of > > the packets they usually refer to of the PPS(packet > > per second)? 64byte? > > > > Thanks > > > > Kent > > > > > > > > > > __ > > Do You Yahoo!? > > Yahoo! Mail - Free email you can access from anywhere! > > http://mail.yahoo.com/ > > > > **NOTE: New CCNA/CCDA List has been formed. For more information go to > > http://www.groupstudy.com/list/Associates.html > > _ > > UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html > > FAQ, list archives, and subscription info: http://www.groupstudy.com > > Report misconduct and Nondisclosure violations to [EMAIL PROTECTED] > > > > > **NOTE: New CCNA/CCDA List has been formed. For more information go to > http://www.groupstudy.com/list/Associates.html > _ > UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html > FAQ, list archives, and subscription info: http://www.groupstudy.com > Report misconduct and Nondisclosure violations to [EMAIL PROTECTED] > **NOTE: New CCNA/CCDA List has been formed. For more information go to http://www.groupstudy.com/list/Associates.html _ UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html FAQ, list archives, and subscription info: http://www.groupstudy.com Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: what is wire-speed?
Wire speed means the switch can pump out packets as fast as the medium can handle. For example, the maximum packets-per-second rate on 10-Mbps Ethernet with 64-byte packets is 14,880 packets per second. This comes from Preamble = 64 bits 64 Byte frame = 512 bits Interframe gap = 96 bits Total = 672 bits Max packets per second on 10 Mbps Ethernet = 10,000,000 / 672 = 14,880 packets per second. A wire-speed switch, which most are, would have no problem outputting that number of packets per second. If you were to use 1024 byte packets, the number is 1197 packets per second on 10Mbps Ethernet. So, yes, vendors do tend to use 64-byte packets when quoting their results, because it gives them better numbers. The other thing vendors do is quote the results when using Gigabit Ethernet. That's where numbers like millions of packets per second come from. In addition, if the vendor's numbers are based on tests that output to multiple ports, then you can get astronomical numbers, for example, 1.48 million packets per second multiplied by 100 ports. As you can probably guess, this is a rudimentary way of specifying the performance of a switch that is fraught with the over-zealousness of marketing drones. &;-) Priscilla At 02:12 PM 9/10/00, Kent wrote: >Hi all, > >Any body knows what they mean by saying "wire-speed" >forwarding about a switch? >Also, when Cisco says a switch can forward at 100 >million pps or something like this, what the size of >the packets they usually refer to of the PPS(packet >per second)? 64byte? > >Thanks > >Kent > > > > >__ >Do You Yahoo!? >Yahoo! Mail - Free email you can access from anywhere! >http://mail.yahoo.com/ > >**NOTE: New CCNA/CCDA List has been formed. For more information go to >http://www.groupstudy.com/list/Associates.html >_ >UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html >FAQ, list archives, and subscription info: http://www.groupstudy.com >Report misconduct and Nondisclosure violations to [EMAIL PROTECTED] Priscilla Oppenheimer http://www.priscilla.com **NOTE: New CCNA/CCDA List has been formed. For more information go to http://www.groupstudy.com/list/Associates.html _ UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html FAQ, list archives, and subscription info: http://www.groupstudy.com Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: what is wire-speed?
64 byte packets and at the max rated pps per port - 14,000 pps something for 10 Mbps Ethernet. However, vendors get cute with the calculation - for example, some, use ingress only while others use ingress and egress - effectively double counting. Others use cumulative ports with oversubscription, which would exceed the backplane and be unreachable. Short answer - don't use pps to buy a switch and ask the vendors 'how' they calculate. --- Kent <[EMAIL PROTECTED]> wrote: > Hi all, > > Any body knows what they mean by saying "wire-speed" > forwarding about a switch? > Also, when Cisco says a switch can forward at 100 > million pps or something like this, what the size of > the packets they usually refer to of the PPS(packet > per second)? 64byte? > > Thanks > > Kent > > > > > __ > Do You Yahoo!? > Yahoo! Mail - Free email you can access from > anywhere! > http://mail.yahoo.com/ > > **NOTE: New CCNA/CCDA List has been formed. For more > information go to > http://www.groupstudy.com/list/Associates.html > _ > UPDATED Posting Guidelines: > http://www.groupstudy.com/list/guide.html > FAQ, list archives, and subscription info: > http://www.groupstudy.com > Report misconduct and Nondisclosure violations to [EMAIL PROTECTED] = Robert Padjen __ Do You Yahoo!? Yahoo! Mail - Free email you can access from anywhere! http://mail.yahoo.com/ **NOTE: New CCNA/CCDA List has been formed. For more information go to http://www.groupstudy.com/list/Associates.html _ UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html FAQ, list archives, and subscription info: http://www.groupstudy.com Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: what is wire-speed?
What do you mean by interfame gap? is it the address? What about ingress and egress issue? how do they calculate it? Thanks a lot Bye On Sun, 10 Sep 2000 19:41:13 -0700, Priscilla Oppenheimer wrote: > Wire speed means the switch can pump out packets as fast as the medium can > handle. For example, the maximum packets-per-second rate on 10-Mbps > Ethernet with 64-byte packets is 14,880 packets per second. This comes from > > Preamble = 64 bits > 64 Byte frame = 512 bits > Interframe gap = 96 bits > > Total = 672 bits > > Max packets per second on 10 Mbps Ethernet = 10,000,000 / 672 = 14,880 > packets per second. A wire-speed switch, which most are, would have no > problem outputting that number of packets per second. > > If you were to use 1024 byte packets, the number is 1197 packets per second > on 10Mbps Ethernet. > > So, yes, vendors do tend to use 64-byte packets when quoting their results, > because it gives them better numbers. > > The other thing vendors do is quote the results when using Gigabit > Ethernet. That's where numbers like millions of packets per second come > from. In addition, if the vendor's numbers are based on tests that output > to multiple ports, then you can get astronomical numbers, for example, 1.48 > million packets per second multiplied by 100 ports. As you can probably > guess, this is a rudimentary way of specifying the performance of a switch > that is fraught with the over-zealousness of marketing drones. &;-) > > Priscilla > > > At 02:12 PM 9/10/00, Kent wrote: > >Hi all, > > > >Any body knows what they mean by saying "wire-speed" > >forwarding about a switch? > >Also, when Cisco says a switch can forward at 100 > >million pps or something like this, what the size of > >the packets they usually refer to of the PPS(packet > >per second)? 64byte? > > > >Thanks > > > >Kent > > > > > > > > > >__ > >Do You Yahoo!? > >Yahoo! Mail - Free email you can access from anywhere! > >http://mail.yahoo.com/ > > > >**NOTE: New CCNA/CCDA List has been formed. For more information go to > >http://www.groupstudy.com/list/Associates.html > >_ > >UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html > >FAQ, list archives, and subscription info: http://www.groupstudy.com > >Report misconduct and Nondisclosure violations to [EMAIL PROTECTED] > > > > > Priscilla Oppenheimer > http://www.priscilla.com > > **NOTE: New CCNA/CCDA List has been formed. For more information go to > http://www.groupstudy.com/list/Associates.html > _ > UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html > FAQ, list archives, and subscription info: http://www.groupstudy.com > Report misconduct and Nondisclosure violations to [EMAIL PROTECTED] ___ Say Bye to Slow Internet! http://www.home.com/xinbox/signup.html **NOTE: New CCNA/CCDA List has been formed. For more information go to http://www.groupstudy.com/list/Associates.html _ UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html FAQ, list archives, and subscription info: http://www.groupstudy.com Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: what is wire-speed?
Thanks guys! Kent --- Priscilla Oppenheimer <[EMAIL PROTECTED]> wrote: > Wire speed means the switch can pump out packets as > fast as the medium can > handle. For example, the maximum packets-per-second > rate on 10-Mbps > Ethernet with 64-byte packets is 14,880 packets per > second. This comes from > > Preamble = 64 bits > 64 Byte frame = 512 bits > Interframe gap = 96 bits > > Total = 672 bits > > Max packets per second on 10 Mbps Ethernet = > 10,000,000 / 672 = 14,880 > packets per second. A wire-speed switch, which most > are, would have no > problem outputting that number of packets per > second. > > If you were to use 1024 byte packets, the number is > 1197 packets per second > on 10Mbps Ethernet. > > So, yes, vendors do tend to use 64-byte packets when > quoting their results, > because it gives them better numbers. > > The other thing vendors do is quote the results when > using Gigabit > Ethernet. That's where numbers like millions of > packets per second come > from. In addition, if the vendor's numbers are based > on tests that output > to multiple ports, then you can get astronomical > numbers, for example, 1.48 > million packets per second multiplied by 100 ports. > As you can probably > guess, this is a rudimentary way of specifying the > performance of a switch > that is fraught with the over-zealousness of > marketing drones. &;-) > > Priscilla > > > At 02:12 PM 9/10/00, Kent wrote: > >Hi all, > > > >Any body knows what they mean by saying > "wire-speed" > >forwarding about a switch? > >Also, when Cisco says a switch can forward at 100 > >million pps or something like this, what the size > of > >the packets they usually refer to of the PPS(packet > >per second)? 64byte? > > > >Thanks > > > >Kent > > > > > > > > > >__ > >Do You Yahoo!? > >Yahoo! Mail - Free email you can access from > anywhere! > >http://mail.yahoo.com/ > > > >**NOTE: New CCNA/CCDA List has been formed. For > more information go to > >http://www.groupstudy.com/list/Associates.html > >_ > >UPDATED Posting Guidelines: > http://www.groupstudy.com/list/guide.html > >FAQ, list archives, and subscription info: > http://www.groupstudy.com > >Report misconduct and Nondisclosure violations to > [EMAIL PROTECTED] > > > > > Priscilla Oppenheimer > http://www.priscilla.com > __ Do You Yahoo!? Yahoo! Mail - Free email you can access from anywhere! http://mail.yahoo.com/ **NOTE: New CCNA/CCDA List has been formed. For more information go to http://www.groupstudy.com/list/Associates.html _ UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html FAQ, list archives, and subscription info: http://www.groupstudy.com Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: what is wire-speed?
At 03:17 AM 9/11/00, you wrote: >What do you mean by interfame gap? is it the address? The interframe gap (IFG) is the required gap between frames. Per the IEEE 802.3 (Ethernet) specification, between frames, there must be silence on the wire for the time to transmit 96 bits, which is 9.6 microseconds on 10 Mbps Ethernet. (I'll let you do the math for the higher speed Ethernets). The IFG gave NICs the time to recover in the olden days when they weren't as fast as they are today. >What about ingress and egress issue? how do they calculate it? Counting ingress would be cheating, if you ask me. I've never heard of a vendor doing that, but I wouldn't put it past them. As we have said, this is all marketing showmanship. Priscilla >Thanks a lot > > Bye > > > > >On Sun, 10 Sep 2000 19:41:13 -0700, Priscilla Oppenheimer wrote: > > > Wire speed means the switch can pump out packets as fast as the medium >can > > handle. For example, the maximum packets-per-second rate on 10-Mbps > > Ethernet with 64-byte packets is 14,880 packets per second. This comes >from > > > > Preamble = 64 bits > > 64 Byte frame = 512 bits > > Interframe gap = 96 bits > > > > Total = 672 bits > > > > Max packets per second on 10 Mbps Ethernet = 10,000,000 / 672 = 14,880 > > packets per second. A wire-speed switch, which most are, would have no > > problem outputting that number of packets per second. > > > > If you were to use 1024 byte packets, the number is 1197 packets per >second > > on 10Mbps Ethernet. > > > > So, yes, vendors do tend to use 64-byte packets when quoting their >results, > > because it gives them better numbers. > > > > The other thing vendors do is quote the results when using Gigabit > > Ethernet. That's where numbers like millions of packets per second come > > from. In addition, if the vendor's numbers are based on tests that output > > > to multiple ports, then you can get astronomical numbers, for example, >1.48 > > million packets per second multiplied by 100 ports. As you can probably > > guess, this is a rudimentary way of specifying the performance of a >switch > > that is fraught with the over-zealousness of marketing drones. &;-) > > > > Priscilla > > > > > > At 02:12 PM 9/10/00, Kent wrote: > > >Hi all, > > > > > >Any body knows what they mean by saying "wire-speed" > > >forwarding about a switch? > > >Also, when Cisco says a switch can forward at 100 > > >million pps or something like this, what the size of > > >the packets they usually refer to of the PPS(packet > > >per second)? 64byte? > > > > > >Thanks > > > > > >Kent > > > > > > > > > > > > > > >__ > > >Do You Yahoo!? > > >Yahoo! Mail - Free email you can access from anywhere! > > >http://mail.yahoo.com/ > > > > > >**NOTE: New CCNA/CCDA List has been formed. For more information go to > > >http://www.groupstudy.com/list/Associates.html > > >_ > > >UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html > > >FAQ, list archives, and subscription info: http://www.groupstudy.com > > >Report misconduct and Nondisclosure violations to [EMAIL PROTECTED] > > > > > > > > > > Priscilla Oppenheimer > > http://www.priscilla.com > > > > **NOTE: New CCNA/CCDA List has been formed. For more information go to > > http://www.groupstudy.com/list/Associates.html > > _ > > UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html > > FAQ, list archives, and subscription info: http://www.groupstudy.com > > Report misconduct and Nondisclosure violations to [EMAIL PROTECTED] > > > > > >___ >Say Bye to Slow Internet! >http://www.home.com/xinbox/signup.html Priscilla Oppenheimer http://www.priscilla.com **NOTE: New CCNA/CCDA List has been formed. For more information go to http://www.groupstudy.com/list/Associates.html _ UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html FAQ, list archives, and subscription info: http://www.groupstudy.com Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: what is wire-speed?
> Date: Sun, 10 Sep 2000 19:41:13 -0700 > From: Priscilla Oppenheimer <[EMAIL PROTECTED]> > Subject: Re: what is wire-speed? > > Wire speed means the switch can pump out packets as fast as the medium can handle. For example, the maximum packets-per- second rate on 10-Mbps Ethernet with 64-byte packets is 14,880 packets per second. This comes from Preamble = 64 bits 64 Byte frame = 512 bits Interframe gap = 96 bits Total = 672 bits > Max packets per second on 10 Mbps Ethernet = 10,000,000 / 672 = 14,880 packets per second. A wire-speed switch, which most are, would have no problem outputting that number of packets per second. > > If you were to use 1024 byte packets, the number is 1197 packets per second on 10Mbps Ethernet. > > So, yes, vendors do tend to use 64-byte packets when quoting their results, because it gives them better numbers. > > The other thing vendors do is quote the results when using Gigabit Ethernet. That's where numbers like millions of packets per second come from. In addition, if the vendor's numbers are based on tests that output to multiple ports, then you can get astronomical numbers, for example, 1.48 million packets per second multiplied by 100 ports. As you can probably > guess, this is a rudimentary way of specifying the performance of a switch that is fraught with the over- zealousness of marketing drones. &;-) > > Priscilla Priscilla Makes some excellent points about switch performance and performance benchmarks. A couple of extra notes on the subject. There are actually some RFCs that cover this topic, namely RFC 1944 (somehwat relevant), RFC 2285 (relevant), RFC 2289 (adds to RFC 2285). Both of the 2200 series RFCs are titled, "Benchmarking Methodology for LAN Switching Devices." Please keep in mind, they are informational, and as such do not represent an Internet Standard. Additionally, there was an excellent Networkers brief that covered this very topic from the bowels of Cisco's testing labs :-) It was pretty informative and if anybody is interested, I can dig up the URL for the presentation. HTH, Paul Werner p.s. The definition of a 64 byte packet?- Ethernet marketing packet :-) Get your own "800" number - Free Free voicemail, fax, email, and a lot more http://www.ureach.com/reg/tag **NOTE: New CCNA/CCDA List has been formed. For more information go to http://www.groupstudy.com/list/Associates.html _ UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html FAQ, list archives, and subscription info: http://www.groupstudy.com Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
