Subject: Ethernet FAQ's This has not been posted for a while, so I am taking the liberty of
posting it:
Q: What is a runt?
A: A packet that is below the minimum size for a given protocol. With
Ethernet, a runt is a frame shorter than the minimum legal length
of 64 bytes (at Data Link).
Q: What causes a runt?
A: Runt packets can be caused accidentally or intentionally. If
accidental, they are most likely the result of a faulty device on
the network, or software gone awry. If intentional, they may be
designed to be runts for a specific reason. SNMP (Simple Network
Management Protocol) is often sent as runt packets so that many
devices will simply ignore it.
Q: What is a jabber?
A: A blanket term for a device that is behaving improperly in terms of
electrical signalling on a network. In Ethernet this is Very Bad,
because Ethernet uses electrical signal levels to determine whether
the network is available for transmission. A jabbering device can
cause the entire network to halt because all other devices think it
is busy.
Q: What causes a jabber?
A: Typically a bad network interface card in a machine on the network.
In bizarre circumstances outside interference might cause it.
These are very hard problems to trace with layman tools.
Q: What is a collision?
A: A condition where two devices detect that the network is idle and
end up trying to send packets at exactly the same time. (within 1
round-trip delay) Since only one device can transmit at a time,
both devices must back off and attempt to retransmit again.
The retransmission algorithm requires each device to wait a random
amount of time, so the two are very likely to retry at different
times, and thus the second one will sense that the network is busy
and wait until the packet is finished. If the two devices retry at
the same time (or almost the same time) they will collide again,
etc.
Q: What causes a collision?
A: See above. Ethernet is a CSMA/CD (Carrier Sense Multiple Access/
Collision Detect) system. It is possible to not sense carrier from
a previous device and attempt to transmit anyway, or to have two
devices attempt to transmit at the same time; in either case a
collision results. Ethernet is particularly susceptible to
performance loss from such problems when people ignore the "rules"
for wiring Ethernet.
Q: What is a jam?
A: When a workstation receives a collision, and it is transmitting, it
puts out a jam so all other stations will see the collision also.
When a repeater detects a collision on one port, it puts out a jam
on all other ports, causing a collision to occur on those lines
that are transmitting, and causing any non-transmitting stations to
wait to transmit.
Q: What is a broadcast storm?
A: An overloaded term that describes an overloaded protocol.
.Basically it describes a condition where devices on the network are
generating traffic that by its nature causes the generation of even
more traffic. The inevitable result is a huge degradation of
performance or complete loss of the network as the devices continue
to generate more and more traffic. This can be related to the
physical transmission or to very high level protocols. There is a
famous example of Banyan Vines bringing a huge network to its knees
because of the addition of a single server, which brought the
network to "critical mass" (this logic error has been corrected).
NFS is famous for this type of failure.
Q: How do I recognize a broadcast storm?
A: That depends on what level it is occurring. Basically you have to
be aware of the potential for it beforehand and be looking for it,
because in a true broadcast storm you will probably be unable to
access the network. This can change dramatically for a higher
level protocol. NFS contention can result in a dramatic DROP in
Ethernet traffic, yet no one will have access to resources.
Q: How can I prevent a broadcast storm?
A: Avoid protocols that are prone to it. Route when it is practical.
Don't buy Ethernet.
.Q: What is *high* traffic on an Ethernet? 5%? 20%? 90%?
A: High traffic is when things start slowing down to the point they
are no longer acceptable. There is not set percentage point, in
other words. Xerox used to use a formula based on packet size over
time, or something, but the issue has been significantly muddied by
the plethora of protocols available and how they react to wire
usage. I usually start paying attention over 40-50%, *or when
things slow down*. I've seen IPX segments that were slow with less
than 20% usage.
Q: What means SQE? What is it for?
A: SQE is the IEEE term for a collision. (Signal Quality Error)
Q: What means "heartbeat"? What is it for?
A: Heartbeat (a.k.a. SQE Test) is a means of detecting a transceiver's
inability to detect collisions. The normal operation of an
Ethernet will test the transceiver's power, transmitter and
receiver; if any of these fail the station will not hear its own
loopback. Without heartbeat, it is not possible to determine if
your collision detector is operating properly. Heartbeat is
implemented by generating a test signal on the collision pair from
the transceiver (or its equivalent) following every transmission on
the network. It does not generate any signal on the common medium.
Note the older usage of this term to refer to the +-.7V carrier
sense wave, although I haven't heard it used that way in a while
(since SQE indicators became popular on transceivers).
Q: What means "CSMA/CD"?
A: Carrier Sense, Multiple Access, with Collision Detection, the MAC
(Media Access Control) algorithm used by Ethernet to help avoid two
devices on the same cable from transmitting at the same time, or at
least recognize when this has happened so that the two devices can
back-off and try again later.
Q: What means "IPG"?
A: The InterPacket Gap (more properly referred to as the InterFrame
Gap, or IFG) is an enforced quiet time of 9.6 us between
transmitted Ethernet frames.
Q: Does a NEMP (Nuclear Electro-Magnetic Pulse) affect an Ethernet?
A: The Russians have done the most research into the effects of NEMP,
although the US and various European countries have also looked
into it. I doubt that the results and theses from this work is
available. Given my very limited understanding of the effect (as a
layman), yes, I expect it would. Obviously, a fiber-optic network
(since it is non-conducting) would have a greater chance for
surviving NEMP. However, I suspect the EMF would not be signif-
icantly retarded by most system enclosures to prevent damage to the
network interface (as well as the rest of the system internals) in
spite of the lack of copper network cables acting as antennae.
Q: What means "promiscuous mode"?
A: A controller in promiscuous mode will receive all frames, regard-
less of destination address. Ethernet is promiscuous in that it
allows any device on a segment to hear every packet on that segment
if the card is so programmed. This is an obvious security issue.
It used to be that there was no way around this besides encoding
the packets themselves, but Synoptics recently released a secure
Ethernet solution (blatant employee plug).
Q: How can I test an Ethernet?
A: You must be more specific. Do you wish to test the electrical
integrity of the wire (ie, will it carry a signal properly) or do
you wish to test the performance of it while running, etc? If the
former, a TDR (see below) or cable scanner that incorporates and
expands on the capabilities of a TDR would be the most
comprehensive tool, though a great deal can be determined with a
simple ohmmeter. The latter requires special and often very
expensive software, usually combined with custom hardware, to
capture, optionally filter, and analyze the network packets. The
most basic test is to connect a pair of devices and see if they can
communicate with each other, while monitoring any status indicators
that the devices might provide.
Q: What is a "TDR"?
A: A Time-Domain Reflectometer is a tool used to detect cable faults.
This device operates by sending a brief signal pulse down the cable
and looking for its reflection to bounce back. By analyzing the
reflected pulse, it is possible to make judgments about the quality
of the cable segment. More advanced units can not only detect and
identify the nature of the problem, but give a reasonably accurate
indication of the problem's location (distance from the point of
the test). There is also a device known as an OTDR, which is an
Optical Time-Domain Reflectometer for fiber-optic cables.
Q: What means "BERT"?
A: Bit Error Rate Tester. This equipment is used to analyze the
amount and types of errors that occur on a cable segment.
Q: What (free) tools are there to monitor/decode/etc an Ethernet?
A: There are many built into most Unix systems. Some cards for the PC
come with utilities. There are several free ones available. Again,
use archie.
Q: What is the difference between an Ethernet frame and a IEEE802.3
frame? Why are there two types? Why is there a difference?
A: Ethernet was invented at Xerox Palo Alto Research Center and later
became an international standard. IEEE handled making it a
standard; and their specifications are slightly different from the
original Xerox ones. Hence, two different types. 802.3 uses the
802.2 LLC to distinguish among multiple clients, and has a "LENGTH"
field where Ethernet has a 2-byte "TYPE" field to distinguish among
multiple client protocols.
TCP/IP and DECnet (and others) use Ethernet_II framing, which is
that which Xerox/PARC originated, while NetWare defaults to 802.3.
Q: What is SNAP
A: Sub-Network Access Protocol
Q: Where can I find out which Protocols use which Ethernet type
numbers?
A: Look at IETF RFC-1340 - Assigned Numbers RFC.
Q: What is UTP, STP?
A: Unshielded twisted pair, shielded twisted pair. UTP is what the
phone companies typically use, though this is not always of high-
enough quality for high-speed network use. STP is mostly from IBM.
Either one can be used for Ethernet, but they have different
electrical characteristics (impedance) and can't be mixed and
matched freely. Some manufacturer's hubs and concentrator cards
can be bought that will speak to either type of cable, so you CAN
hook them together in a manner.
Q: What exactly means 10Base5, 10BaseT, 10Base2, 10Broad36, etc.
A: The "10" stands for signalling speed: 10MHz. "Base" means Baseband,
"broad" means broadband. Initially, the last section as intended
to indicate the maximum length of an unrepeated cable segment.
This convention was modified with the introduction of 10BaseT,
where the T means twisted pair, and 10BaseF where the F means
fiber (see the following Q&A for specifics). This actually comes
from the IEEE committee number for that media.
In actual practice:
10Base-2 Is 10MHz Ethernet running over thin, baseband coax.
10Base-2 is also commonly referred to as thin-Ethernet
or Cheapernet.
10Base-5 Is 10MHz Ethernet running over standard (thick) base-
band coax.
10Base-F Is 10MHz Ethernet running over fiber-optic cabling.
10Base-T Is 10MHz Ethernet running over unshielded, twisted-
pair cabling.
Q: Are there any restrictions on how Ethernet is cabled?
A: Yes, there are many, and they vary according to the media used.
First of all, there are distance limitations:
10Base-2 limited to 185 meters (607 ft) per unrepeated cable
segment.
10Base-5 limited to 500 meters (1,640 ft) per unrepeated cable
segment.
10Base-F depends on the signaling technology and medium used
but can go up to 2KM.
10Base-T generally accepted to have a maximum run of 100-150M,
but is really based on signal loss in db's (11.5db
maximum loss source to destination).
Then there are limitations on the number of repeaters and cable
segments allowed on a single network. There may be no more than
five (5) repeated segments, nor more than four (4) repeaters on any
Ethernet; and of the five cable segments, only three (3) may be
populated. This is referred to as the "5-4-3" rule (5 segments, 4
repeaters, 3 populated segments). It can really get messy when you
start cascading through 10Base-T hubs, which are repeaters unto
themselves. Just try to remember, that any possible path between
two network devices on an unbridged/unrouted network cannot pass
through more than 4 repeaters or hubs, nor more than 3 populated
cable segments.
Finally, 10Base-2 is limited to a maximum of 30 network devices per
unrepeated network segment with a minimum distance of 0.5m (1.5ft)
between T-connectors. 10Base-5 is limited to a maximum of 100
network devices per unrepeated segment, with a minimum distance of
2.5m (8.2ft) between taps/T's (usually indicated by a marker
stamped on the cable itself every 2.5m).
I am not aware of any theoretical limit on the number of 10Base-T
devices, and don't know the limitations for 10Base-F yet. (Can
someone fill-in the blanks?)
Q: What is 10Base-F?
A: 10Base-F is an IEEE standard for 10mbps Ethernet over fiber-optic
cabling. It defines the methodology and standard devices which,
ideally, can permit one company's 10Base-F devices to interoperate
with any others'.
Q: What means FOIRL?
A: Fiber Optic Inter Repeater Link. A "IEEE 802 standard" worked out
between many vendors some time ago for carrying Ethernet signals
across long distances via fiber optic cable. It has since been
adapted to other applications besides connecting segments via
repeaters (you can get FOIRL cards for PCs). It has been
superseded by the larger 10Base-F standard.
Q: What about wireless LAN's? Are there any?
A: Yes. They typically use reflected or point-to-point infrared
light, spread-spectrum RF or microwave RF transmission as as media.
They are typically expensive, slow (relative to Ethernet) and are
not yet a mature technology. There are special applications for
light based (laser) repeaters.
Q: When should I choose 10BaseT, when 10Base2 (or others)?
A: The specific environment and application must be considered when
selecting your media type. However, there are some general rules-
of-thumb that you can consider:
Avoid using copper between buildings. The electrical disturbances
caused by lightning, as well as naturally occurring differences in
ground potential over distance, can very quickly and easily cause
considerable damage to equipment and people. The use of fiber-
optic cabling between buildings eliminates network cabling as a
safety risk. There are also various wireless media available for
inter-building links, such as laser, spread-spectrum RF and micro-
wave. However, wireless media is much more expensive and less
reliable than fiber-optic, and should only be considered when it is
impossible to get right-of-way for fiber-optic cable.
10Base-2 (thin Ethernet or Cheapernet) is the least expensive way
to cable an Ethernet network. However, the price difference
between 10Base-2 and 10Base-T (Ethernet over UTP) is rapidly
diminishing. Still, for small, budget-conscious installations,
10Base-2 is the most economical topology. The disadvantages of
10Base-2 is that any break in the cable or poor connection will
bring the entire network down, and you need repeaters if you have
more than 30 devices connected to the network or the cable length
exceeds 185 meters (607 feet).
10Base-5 is generally used as a low-cost alternative to fiber-optic
media for use as a backbone segment within a single building. It's
extended length (500m or 1640ft), higher attached device count
(100) and better noise resistance make 10Base-5 well suited for use
as a network trunk for one or more floors in a building. However,
the high cost of connecting each device (in addition to the
interface, you also need an external transceiver, or MAU, and an
AUI cable) makes 10Base-5 too expensive for most LAN installations,
and like 10Base-2, a single break or bad connection in the cable
can bring the entire network down.
10Base-T is the most flexible topology for LANs, and is generally
the best choice for most network installations. 10Base-T hubs, or
multi-hub concentrators, are typically installed in a central
location to the user community, and inexpensive UTP cabling is run
to each network device (which may be 100m, or 330ft, from the hub).
The signalling technology is very reliable, even in somewhat noisy
environments, and 10Base-T hubs will usually detect many network
error conditions and automatically shut-down the offending port(s)
without affecting the rest of the network (unless, of course, the
offending port was your server, shared printer, or router to the
rest of the world). While the hardware is more expensive than
10Base-2, the cabling is cheaper and requires less skill to
install, making 10Base-T installation costs only slightly higher
than 10Base-2. The flexibility and reliability more than offset
the marginally higher price.
10Base-F, and its predecessor, FOIRL, are the only recommended
topologies for inter-building links. However, they need not be
limited to this role. 10Base-F can also be run to the desktop,
though the cost is prohibitively high in all but the most
specialized environments (generally, extremely noisy manufacturing
facilities, or very security-conscious installations). More
commonly, FOIRL (and now, 10Base-F) is used inside buildings to
form backbone networks and to connect wiring closets together.
Q: What are the advantages/disadvantages of a star like cabling?
A: Old style Ethernet bus wiring (ie, taking the cable from one
machine to the next, and then to the next, etc) is prone to cable
failure and quickly consumes allowed distances due to aesthetic
wiring needs. If the wiring connection is broken at any point, the
entire network (segment) fails - and the much greater number of
connections increases the probability of a failure or break. On the
other hand, it's pretty easy to do for a layman and may involve
less actual wiring for small segments.
Star wiring eliminates the single point of failure of a common
wire. A central hub has many connections that radiate out to hosts,
if one of these hosts connections fails it usually doesn't affect
the others. Obviously, however, the hub becomes a central point of
failure itself, but studies show a quality hub is less likely to
fail before a heavily used strand of coax.
There are a bunch of other reasons hubs are desirable, but this is
the biggie.
Q: Is there an official "standard" punch down scheme for 10BaseT?
A: Get a copy of EIA-568, it covers all of that sort of stuff:
horizontal, vertical, connectors, patch cords, cross-connects, etc.
Q: Is it safe to run Unshield Twisted Pair next to power cable (it is
shielded)?
A: According to EIA/TIA-569, the standard wiring practices for running
data cabling and companion to the above referenced EIA/TIA-568, you
should not run data cable parallel to power cables. However, in
reality, this should not be a problem with networks such as
10Base-T. 10Base-T uses differential signalling to pick the data
signals off the wire. Since any interference from nearby power
lines will usually affect all pairs equally, anything that is not
canceled-out by the twists in the UTP should be ignored by the
receiving network interface.
Q: Why has the MAC address to be unique?
A: Each card has a unique MAC address, so that it will be able to
exclusively grab packets off the wire meant for it. If MAC
addresses are not unique, there is no way to distinguish between
two stations. Devices on the network watch network traffic and
look for their own MAC address in each packet to determine whether
they should decode it or not. Special circumstances exist for
broadcasting to every device.
Q: Is there a special numbering scheme for MAC addresses?
A: The MAC addresses are exactly 6 bytes in length, and are usually
written in hexadecimal as 12:34:56:78:90:AB (the colons may be
omitted, but generally make the address more readable). Each
manufacturer of Ethernet devices applies for a certain range of MAC
addresses they can use. The first three bytes of the address
determine the manufacturer. RFC-1340 (available via FTP) lists
some of the manufacturer-assigned MAC addresses.
Q: What is a "segment"?
A: A piece of wire bounded by bridges, routers, or terminators. Some
people consider wires on either side of a repeater separate
segments, but they aren't really.
Q: What is a "subnet"?
A: Another overloaded term. It can mean, depending on the usage, a
segment, a set of machines grouped together by a specific protocol
feature (note that these machines do not have to be on the same
segment, but they could be) or a big nylon thing used to capture
soviet subs.
Q: What is a fan-out? Is this device still used?
A: Fanout (a.k.a transceiver multiplexor, a.k.a. multiport trans-
ceiver, a.k.a. DELNI) allows multiple stations to connect to a
single transceiver or transceiver-like device. They are still
widely used.
Q: What means "AUI"?
A: Attachment Unit Interface, an IEEE term for the connection between
a controller and the transceiver.
Q: What is a transceiver?
A: A transceiver allows a station to transmit and receive to/from the
common medium. In addition, Ethernet transceivers detect collisions
on the medium and provide electrical isolation between stations.
Q: What means "MAU"?
A: Medium Access Unit, an IEEE term for a transceiver. MAU is also
commonly [mis]used to describe a Token-Ring Multi-Station Access
Unit (MSAU). Refer to HUB for an explanation of MSAU.
Q: What exactly does a repeater?
A: A repeater acts on a purely electrical level to connect to
segments. All it does is amplify and reshape (and, depending on the
type, possibly retime) the analog waveform to extend network
segment distances. It does not know anything about addresses or
forwarding, thus it cannot be used to reduce traffic as a bridge
can in the example above.
Q: What is a "HUB"?
A: A hub is a common wiring point for star-topology networks, and is a
common synonym for concentrator (though the latter generally has
additional features or capabilities). Arcnet, 10Base-T Ethernet and
10Base-F Ethernet and many proprietary network topologies use hubs
to connect multiple cable runs in a star-wired network topology
into a single network. Token-Ring MSAUs (Multi-Station Access
Units) can also be considered a type of hub, but don't let a
token-ring bigot hear that. Hubs have multiple ports to attach
the different cable runs. Some hubs (such as 10Base-T and active
ArcNet) include electronics to regenerate and retime the signal
between each hub port. Others (such as 10Base-F or passive Arcnet)
simply act as signal splitters, similar to the multi-tap cable-TV
splitters you might use on your home antenna coax (of course,
10Base-F uses mirrors to split the signals between cables).
Token-Ring MSAUs use relays (mechanical or electronic) to reroute
the network signals to each active device in series, while all
other hubs redistribute received signals out all ports
simultaneously, just as a 10Base-2 multi-port repeater would.
Q: What exactly does a bridge?
A: A bridge will connect to distinct segments (usually referring to a
physical length of wire) and transmit traffic between them. This
allows you to extend the maximum size of the network while still
not breaking the maximum wire length, attached device count, or
number of repeaters for a network segment.
Q: What does a "learning bridge"?
A: A learning bridge monitors MAC (OSI layer 2) addresses on both
sides of its connection and attempts to learn which addresses are
on which side. It can then decide when it receives a packet
whether it should cross the bridge or stay local (some packets may
not need to cross the bridge because the source and destination
addresses are both on one side). If the bridge receives a packet
that it doesn't know the addresses of, it will forward it by
default.
Q: What is a remote bridge?
A: A bridge as described above that has an Ethernet (or token-ring)
interface on one side and a serial interface on the other. It
would connect to a similar device on the other side of the serial
line. Most commonly used in WAN links where it is impossible or
impractical to install network cables. A high-speed modem (or T1
DSU/CSU's, X.25 PAD's, etc) and intervening telephone lines or
public data network would be used to connect the two remote bridges
together.
Q: What exactly does a router?
A: Routers work much like bridges, but they pay attention to the upper
network layer protocols (OSI layer 3) rather than physical layer
(OSI layer 1) protocols. A router will decide whether to forward a
packet by looking at the protocol level addresses (for instance,
TCP/IP addresses) rather than the MAC address. Because routers
work at layer 3 of the OSI stack, it is possible for them to
transfer packets between different media types (i.e., leased lines,
Ethernet, token ring, X.25, Frame Relay and FDDI). Many routers
can also function as bridges. Routing would always be preferable
to bridging except for the fact that routers are slower and usually
more expensive (due to the amount of processing required to look
inside the physical packet and determine which interface that
packet needs to get sent out).
Q: So should I use a router or a bridge?
A: There is no absolute answer to this. Your network layout, type and
amount of hosts and traffic, and other issues (both technical and
non-technical) must be considered. The following are the pros and
cons of each:
Routing:
+ Can route between different media (although FDDI to Ethernet
bridges are becoming common via the Translation Bridging
standard).
+ There is isolation of Multicast & Broadcast packets at the
MAC layer which helps to reduce broadcast storms.
+ Can run multiple active paths between sites in a mesh network
to use links efficiently (bridging uses spanning tree to
decide if a link is forwarding or in a back up state).
+ Takes part in higher level protocol so can provide more
features (examples = logical zones in Appletalk, proxy ARP on
IP).
+ Provide a clean cut off when connecting multiple management
domains.
+ Only needs to know 'where next?' and so hides the detail of
remote networks, whereas bridges must understand the whole
topology of the net.
Bridging:
+ Much cheaper boxes.
+ Learning bridges virtually autoconfigure themselves.
+ Works with any protocol that conforms to the MAC level spec.
some protocols such as DEC LAT & MOP can only be bridged.
+ Within a site uses IP address space more efficiently whilst
providing some traffic segregation (address space is becoming
a real scarce resource!).
+ Bridges are generally less complex devices, which usually
translates to higher reliability.
+ Easy inter-vendor working via spanning tree standard (802.1d
or DEC STP)
Q: Are there problems mixing Bridging & routing?
A: You should be very careful about running bridges providing links in
parallel to a router. Bridges may forward broadcast requests which
will confuse the router there are lots of protocols you may not
think of filtering (e.g. ARP, Apple ARP over 802.3 etc. etc.).
Also, DECnet routers have the same MAC address on all ports. This
will probably cause the bridge to think it is seeing an Ethernet
loop.
Q: What is a Kalpana EtherSwitch?
A: A device that works sort of like a bridge, but off a different
principle. It's advantages are that it is extremely fast and can
"bridge" more than one packet at a time (it is not limited to two
interfaces as a traditional bridge is). Disadvantages are that it
does not understand spanning tree and doesn't work well in many to
one networks. You probably don't understand that, so ignore it.
Q: What is a driver?
A: Typically the software that allows an Ethernet card in a computer
to decode packets and send them to the operating system and encode
data from the operating system for transmission by the Ethernet
card through the network. By handling the nitty-gritty hardware
interface chores, it provides a device-independent interface to the
upper layer protocols, thereby making them more universal and
[allegedly] easier to develop and use. There are many other
meanings to this word, but this is probably what you are looking
for.
Q: What is NDIS, packet driver, ODI.?
A: NDIS is a Microsoft/3com puppy that allows "stacking" of multiple
protocols for a single underlying driver. Essentially it allows a
single Ethernet card in a PC (it's not limited to Ethernet) to
speak many different network "languages", and usually at the same
time.
A packet driver is another method of allowing multiple protocols to
access the network interface at the same time. Developed and
supported by FTP Software Inc, Clarkson University, BYU and, more
recently, Crynwr Software, the packet driver spec (PDS) is used to
provide a device independent interface to various TCP/IP applica-
tions, and often in combination with concurrent Novell access
(IPX/SPX).
ODI is Novell and Apple's equivalent of NDIS. There are differ-
ences between the two specs, but not so much as to warrant descrip-
tion in this text.
The next logical question is "which one should I use?" There is no
simple or obvious answer, except that you should use the one most
commonly required by your software.
Q: Is there a troubleshooting guide for Ethernet?
A: Many. I suggest you check your local technical bookstore.
(Recommendations needed)
Q: What books are good about Ethernet LAN's?
A: There are many. The following are recommended by readers on this
list:
"The Ethernet Management Guide - Keeping the Link" by Martin
Nemzow. This book has good coverage of most of the average
considerations of Ethernet, from what Manchester encoding is down
to production segment traffic analysis.
Q: Where can I get IEEE803.x docs online?
A: Nowhere. IEEE documents must be ordered from the IEEE themselves.
You can contact them at:
Institute of Electrical and Electronic Engineers
445 Hoes Lane
P.O. Box 1331
Piscataway, NJ 08855-1331
U.S.A.
(800) 678-IEEE
Q: Where can I get EIA/TIA docs online?
A: Nowhere? Must be ordered from:
Global Engineering
2805 McGaw Av
Irvine, CA 92714
phone 714-261-1455
Q: Where can I find the specifications of Ethernet equipment?
A: From the manufacturer of the product, probably.
Q: Where can I find IETF (Internet Engineering Task Force) documents?
A: These are available for anonymous FTP from a number of sites. One
known location is athos.rutgers.edu in /ietf. Drafts are also on
athos in /internet-drafts. [/b]