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Peavey Electronics ®2006 AV-IT CONVERGENCE IT’S WHAT THE WORLD IS COMING TO, ALFIE Peavey Electronics ®2006 Ethernet or 802.3? You may have heard the term 802.3 used in conjunction with the term Ethernet. "Ethernet" originally referred to a networking implementation standardized by Digital, Intel and Xerox. (it is also known as the DIX standard). In February 1980, the Institute of Electrical and Electronics Engineers, or IEEE (pronounced "I triple E"), created a committee to standardize network technologies. This was named the 802 working group, named after the year and month of its formation. Peavey Electronics ®2006 Subcommittees of the 802 working group separately addressed different aspects of networking. The IEEE distinguished each subcommittee by numbering it 802.X. The 802.3 group standardized the operation of a CSMA/CD network that was functionally equivalent to the DIX Ethernet. Though Ethernet and 802.3 differ slightly, the term Ethernet refers generically to both the DIX Ethernet implementation and the IEEE 802.3 standard. Peavey Electronics ®2006 Ethernet Terminology Ethernet follows a simple set of rules that govern its basic operation. To better understand these rules, it is important to understand the basics of Ethernet terminology. Peavey Electronics ®2006 Ethernet Terminology •Medium - Ethernet devices attach to a common medium that provides a path along which the signals will travel. Originally, this medium was coaxial copper cable, but today it is a twisted copper pair, fiber optic cabling, and now a new emerging transport, wireless (RF and IR). Peavey Electronics ®2006 •Segment - We refer to a single shared medium as an Ethernet segment, Network, or LAN. This segment would be the entire run of coax back when that was the standard media. You could divide a segment by placing a “Bridge” somewhere in the middle of the run. This device would then bridge those now two segments (but do not confuse this with creating a vLAN). Bridges will be important when discuss “Switches” later. Peavey Electronics ®2006 •Node - The devices that attach to that segment (such as a computers, printers, Nions, CABs, etc.) are referred to as nodes. •Frame - The nodes communicate in short messages called frames, which are variably sized chunks of information. Peavey Electronics ®2006 Frames are sometime referred to as Packets, Tokens, and occasionally as Data Segments, along with other names depending on the Protocol. The technically correct term for the complete data package for 802.3 is Frame. But because all protocols use a frame somewhere within the protocol, frame is the most common name for these “chunks of data”. Peavey Electronics ®2006 Frames are analogous to sentences in human language. In English, we have rules for constructing our sentences: We know that each sentence must contain a subject and a verb. Likewise, each Ethernet protocol specifies a set of rules for constructing frames. There are explicit minimum and maximum lengths for frames, and a set of required pieces of information that must appear in the frame. Peavey Electronics ®2006 Each frame must include, for example, both a destination address and a source address, which identify both the recipient and sender, which uniquely identifies the node, just as a name identifies a particular person. Peavey Electronics ®2006 The Basic IEEE 802.3 MAC Format Peavey Electronics ®2006 This is a CSMA/CD network, which is the basis of the 802.3 Ethernet standard. Carrier Sense - Nodes listens to the media to confirm that it is clear. Multiple Access - Many nodes using the same media. Collision Detection - Detects if another node starts to transmit at the same time. Peavey Electronics ®2006 Nodes listen to the medium while they transmit to ensure that they are the only node transmitting at that time. If the nodes hear their own transmission returning in a garbled form, as would happen if some other node had begun to transmit its own message at the same time, then they know that a collision occurred. Peavey Electronics ®2006 A single Ethernet segment is sometimes called a collision domain because no two nodes on the segment can transmit at the same time without causing a collision. When nodes detect a collision, they cease transmission, wait a random amount of time, and attempt to transmit when they again detect silence on the medium. Peavey Electronics ®2006 If you have too many nodes on a network (the result would be too many collisions, slowing the network down), you can use an “Ethernet Bridge” to create two smaller networks segments. We are not going into depth on Bridges, as these are rarely seen anymore. Peavey Electronics ®2006 One last piece of information before we leave the subject CSMA/CD networks. A Switch creates an Ethernet segment between the switch and each node. This is sometimes called a “collisionless domain” because no two nodes are on the same segment. But we will get back to Switches later. Peavey Electronics ®2006 568A Many may remember COAX as the standard for networking cabling, whether it was RG-11 (Thick-Net), or RG-58 (Thin-Net). Most of the time, if a simple problem occurred at only one node, the entire network would stop working. Peavey Electronics ®2006 So, a new standard was created within 802.3 called 568A, which brought the “Hub” or “Star” network into being. A hub consists of multiple repeaters all in one box, with a node connected to each port, commonly called a star layout. This solved so many of the original problems from using coax, that most other protocols adapted the star architecture, including Token Ring. Peavey Electronics ®2006 But 568A can be confusing because with in this standard is two RG-45 pin-out configurations, 568A and 568B. So, you could be using 568B pin-out (which is the more common), but you are still using the 568A standard. Confused yet? Don’t worry, you are not alone, most IT managers don’t know this stuff. Bottom line, make sure you are using the “building standard” (ask the cable installer). But it is getting trickier.... More on that in a couple slides. Peavey Electronics ®2006 At the center of the star is a device known as a HUB, but the function of the network remains the same, using CSMA/CD. A hub is merely an active repeater that restores the “square” to the square wave. You must not confuse hubs with a switch, as all connected hubs (and all connected nodes) are on a single collision domain--segment. Peavey Electronics ®2006 568A So along comes Category 1, which was not much better than POTS (Plain Old Telephone Service). Cat 2, of which there is a little of this still in use today, because IBM went long on this one. It runs at 4 Mbps. Cat 3, also know as 10baseT and as Ethernet, and ran at 10Mbps. Cat 4, didn’t last long and had very limited installs, as it ran at 17Mbps, and Cat 5 was out about 18 months later. Peavey Electronics ®2006 568A A quick sidebar. The main difference between each of the category “levels” is the amount of “twists per inch” of the cable. Each pair within a cable has a different rate of twist, the blue from the orange, etc. Also important is how the pairs run inside the outer jacket in relationship with each other. This all impacts noise rejection and crosstalk. Peavey Electronics ®2006 568A Cat 5, also known as 100baseT or Fast Ethernet, and runs (we will change to present sense here) at 100 Mbps. Cat 5e and Cat 5E, were hardware (cable and connectors) changes that enabled higher bandwidth. These new categories were addendums to 568A, and not really new standards. Cat 5=100MHz, Cat 5e=150MHz, Cat 5E=350MHz Peavey Electronics ®2006 568B Cat 6, almost 10 years after the original Cat 5, and was ratified in April of 2002 as the 568B Standard. I warned you it would get tricky! FYI. When Cat 7 is finished, it will be the 568C Standard, and supposed to run at Ten-Gig. Peavey Electronics ®2006 568B So we finally have Cat 6, which enables 1000baseT, or Gigabit Ethernet. But remember this.... Just because the infrastructure (cable and jacks) are Cat 6, doesn’t mean you should use Gigabit copper. Be wary of the electronics, most are problematic at this time, but hardware is improving all the time…..BUT!!!!! Peavey Electronics ®2006 568B Most AV content that is riding on ethernet is mission critical, meaning that lost packets are, well, exactly that...LOST. Gone forever. It can’t be resent like “regular” computer data. Peavey Electronics ®2006 568B For video, lost packets would create “video noise” at a minimum, a blank screen at worse. With CobraNet, a few lost packets will sound like distortion, a few more will sound like scratching on a mic’s windscreen, a few more and audio will stop. Peavey Electronics ®2006 568B So again, and this is important, if you need Giga-speed, go fiber! Another issue with AV devices that just use the cabling infrastructure (not going thru the switches, just the cable), they don’t always work with Cat 6. The changes in twists of the cable (in comparison to Cat 5) cause too much “skew”, so the signals cannot be put back together correctly. Peavey Electronics ®2006 We mentioned earlier that a switch creates a collisionless domain by creating a separate segment between each port on the switch and the attached node. So though switches look similar to a hub, they are functionally very different from a hub. The biggest difference being this dedicated segment for every node on the network. Peavey Electronics ®2006 Switched Ethernet This is perhaps the most striking advancement in contemporary Ethernet networks is the use of “Switched Ethernet”. Many AV devices are requiring switches instead of hubs, so we are going to spend some time here. Peavey Electronics ®2006 Switched Ethernet Switched networks replace the shared medium of legacy Ethernet (coax, hubs, and repeaters) with a dedicated segment for each node. Remember we talked earlier about the hub being just many repeaters in one box? Well, a switch is many Ethernet Bridges in one box. And what did I say a bridge does? Peavey Electronics ®2006 Switched Ethernet It divides a network into separate segments, creating a Collisionless Domain. When a node is connected to a port on a switch, it creates a single, separate segment between the switch and that node. Some interconnected switches can support thousands of dedicated segments, for example, the Internet. Peavey Electronics ®2006 Switched Ethernet Because switches have become so affordable, we in tech support are recommending that mission critical data be on a separate physical network, or “LAN” (Local Area Network), in most installs. This minimizes any conflicts that can (and frequently do) occur. We have always recommended this for large installs, but with a different twist. We’ll discuss this in a moment. Peavey Electronics ®2006 Switched Ethernet In a (very) small install, where there are few nodes, and where few broadcasts occur (which goes to all ports of a switch), a single switch can be used. But with most installs, it makes sense to create that separate network for the mission critical data. Lets take audio as an example. Peavey Electronics ®2006 Switched Ethernet During the design phase, put the cost of two inexpensive (but not “cheap”) switches in the quote. This way, you have two “physical” LANs in place. Another sidebar; why would you put the “mission critical” part of a tens of thousand dollar project on a $35 switch???? Peavey Electronics ®2006 Switched Ethernet On one LAN (switch), all of the CobraNet related devices are connected. And on the second LAN (switch), any required CPU’s NIC (Network Interface Card) are connected, along with all the other “control” type devices, such as Nion and Crestron/AMX. So in a single closet install, there would be two switches, one for the control devices and the other for the CobraNet devices (two physical LANs). Peavey Electronics ®2006 Switched Ethernet In a multiple closet install, any audio closet where a control device and a CobraNet device co-exist, there would be two switches (the two physical LANs). Four good, low cost, simple switches, and two 100 Mbps channels from one closet to another will cost less than one good low cost “managed” switch and one 100 Mbps channel. Peavey Electronics ®2006 Another sidebar; Because A/V is sharing closets more and more with the IT/Phone people, we need to learn the jargon. A MDF (Main Distribution Frame) is the “focal” point of the star layout, an IDF (Intermediate Distribution Frame) are the closets that, because of distance restraints, gather up outlaying stars and “relay” them back to the MDF. Peavey Electronics ®2006 The Managed Network A big install is a different story. On the last install that I was involved on before coming to Peavey, ten separate networks were required by the A-V and lighting system! Two for lighting, four for CobraNet, three for control and admin, and one for nodes that I wanted to keep contained in their own little world. A Managed Switch using “VLANs” is the only answer for this type of install. Peavey Electronics ®2006 The Managed Network Managed switching (the heart of a managed network) has been around for a long time, and as with everything to do with computers, has become much more affordable. One of the best things (among many other fun stuff) about a managed switch is that you can create “Virtual Local Area Networks” or VLANs. Peavey Electronics ®2006 The Managed Network Virtual LANs divide up a switch into two or more networks, on a port by port basis. For example, ports 1 & 2 would be in one network, ports 3 thru 6 in another, 7 thru 12 in another, etc. So a single managed switch can be setup as if there were many switches, dividing up and isolating any conflicts with network traffic. Peavey Electronics ®2006 The Managed Network But there is one caveat, whether you are using two physical networks or VLANs. Because the nodes on one network (or VLAN) can't talk to another network, a gateway may be required. A gateway could be as simple as putting in a second NIC in any device that needs to talk to two VLANs, making that device into a gateway. Peavey Electronics ®2006 The Managed Network A router is also a gateway device, and is the most common way to route data traffic from one network to another. Now some will say that you could instead use Layer 3 or Smart Switches, and that is true. But, Layer 3 switches are running some type of router software, somewhere. So it could be less expensive to go with a router and a Layer 2 switch solution. Peavey Electronics ®2006 The Managed Network A managed switch can also provide a means to expedite time-critical (CobraNet) network traffic by setting transmission priorities for outgoing frames. This can be critical if a 100Mbps backbone is being used. Peavey Electronics ®2006 Corporate LAN Router Switch Switch Switch Peavey Electronics ®2006 Switch Switch Router Switch Peavey Electronics ®2006 Product Peavey Electronics ®2006 5 Port Workgroup Switch Peavey Electronics ®2006 16 Port Workgroup Switch Linksys SR216 Peavey Electronics ®2006 24 Port Managed Switch Linksys ProConnect II 2224 Peavey Electronics ®2006 24 Port (plus 2 GBIC Module) Layer 3 Switch Cisco 2950g Peavey Electronics ®2006 A configurable, routing capable, Switch Cisco 4506 Peavey Electronics ®2006 802.3 Because it is still about convergence Peavey Electronics ®2006 Peavey Electronics ®2006 Layer 7, Application: This layer provides network services directly to the user's application such as a web browser, email or NWare software. Other protocol's that operate here are: Telnet, which would connect to HyperTerminal, HTTP to Window’s Explorer, SMTP to Outlook, FTP, TFTP, NTP, SNMP, and EDI. Peavey Electronics ®2006 Layer 6, Presentation: This layer formats the data ready to be presented to the Application layer. It defines encryption, compression, conversion and other coding functions. Good examples of this are: GIF, TIFF, JPEG, and MPEG. Peavey Electronics ®2006 Layer 5, Session: This layer establishes, maintains and terminates end-to-end connections (sessions) between two network nodes. It controls the dialogue between the source and destination node, when the node can send and how long for. This layer also provides error reporting for the Application, Presentation and Session layer. Peavey Electronics ®2006 Layer 4, Transport: This layer is responsible for endto-end delivery of data and provides services such as error checking and flow control. Protocols that operate on this layer: TCP, UDP, NETBEUI, SPX. Peavey Electronics ®2006 Beginning here at the transport layer, the raw data streams start the process of being divided into Frames. On this layer the data is divided into segments, this process creates the data/pad part. Flow control is integrated into the process to guarantee that each segment is being delivered at the correct rate. Peavey Electronics ®2006 Here is an important analogy that we will come back to later. Think of a water hose (the raw data stream) filling a defined size bucket (the explicit length of data). Peavey Electronics ®2006 The bigger the bucket, the longer it will take the hose to fill the bucket to capacity so it can be handed off to the next layer. So why is this important...The latency that this adds, but more on this later. Peavey Electronics ®2006 Now, another important thing to remember at the transport layer is that the protocols are either connectionless or connectionoriented: Peavey Electronics ®2006 Connection-oriented means that a connection must be established before data can be exchanged (in other words, you know which way to go as you have a set of instructions). This can guarantee that data will arrive at it's destination, and in the same order it was sent. Peavey Electronics ®2006 It guarantees that delivery by sending acknowledgements back to the source when messages are received. TCP is an example of an connection-oriented transport protocol! Connectionless is when the sender does not establish a connection before it sends data. It just sends without a guarantee of delivery. Peavey Electronics ®2006 Here is an example of both; Connection FTP (File Transfer Protocol)--Each packet sent is acknowledged by the receiving node. This process is usually windowed, 5 packets sent before an acknowledgement is returned, acknowledging all 5 of those packets. Connectionless TFTP (Trivial File Transfer Protocol) Packets are not acknowledged, which makes the process faster. Peavey Electronics ®2006 Layer 3, Network: This layer provides the logical addressing of the node and network segments, which is required if the data needs routing, which enables data to be passed from one network to another. Protocols used at this layer are: IP, IPX, AppleTalk, RIP, BGP, IGRP. Peavey Electronics ®2006 This is where many protocols begin to become a stacked (such as TCP/IP, SPX/IPX) packet. These stacked protocols are sometimes known as “Layer 3” addressing. This address structure determines which network the node is on and the individual node address on that network. It is worth making clear that the already mentioned Layer 3 switches and Routers operate at this layer. Peavey Electronics ®2006 The process of creating a Frame contunies. By adding Logical Addressing on this layer, the segment becomes a Packet. Peavey Electronics ®2006 Layer 2, Data Link: This layer actually consists of two sub-layers: LLC at the upper layer (Logical Link Control) and at the lower level is the MAC (Media Access Control). Peavey Electronics ®2006 Have you heard the term MAC address before? The MAC address resides in the data link layer! Devices that use this layer (layer 2) are routers, switches, and bridges. By adding MAC Addressing on this layer, the Packet now becomes a Frame. Peavey Electronics ®2006 This is where much of CobraNet magic occurs, which is why we are taking the time to talk about the OSI Model. More on that later. Peavey Electronics ®2006 Layer 1, Physical: This layer defines the actual physical specifications, either copper (UTP/sUTP/coax/etc), fiber, or wireless. It handles the raw bit stream by creating either electrical, light, or RF bit streams, placing it on the medium to be picked up by the Physical layer at the receiving node. Peavey Electronics ®2006 It is responsible for activating, maintaining and deactivating the physical link. The Physical Layer defines electrical (voltage), light signaling (wavelength), or radio signaling (frequency). Transmission rates and distances, mechanical specifications (cable lengths, and type of connector). Peavey Electronics ®2006 Devices that operate on this layer are hubs, repeaters, NIC's, and interfaces such as RS-232, OC-3, BRI, X.25 and Frame Relay. Peavey Electronics ®2006 Here is another graphic to show how it all works Data Streaming from the Application Layer to the Session Layer Divided into Segments on the Transport Layer Adding Logical Addressing create Packets Adding the MAC Address create the Frame Peavey Electronics ®2006 OSI Model OK, why have you just poured all this information into that hole in my head, it is already leaking out!!! Because the IT department lives and breathes this stuff. Because if you understand this model, you can troubleshoot many network problems. Peavey Electronics ®2006 The Bottom Line Take the time to learn the IT department’s language Understanding another’s language Is the art of communicating. Peavey Electronics ®2006 The OSI Model Peavey Electronics ®2006 The TCP/IP Protocol Stack Peavey Electronics ®2006 The CobraNet Stack Peavey Electronics ®2006 Internet Protocol Suite Application BOOTP Transport Network SNMP TFTP UDP RARP* ARP ICMP* IP Logical Link 802.3 Ethernet Physical Fast Ethernet Interface * PARTIAL SUPPORT CobraNet Services Cobra Net Audio Serial Bridge Packet Bridge Peavey Electronics ®2006 CobraNet Conductor A CobraNet network would consist of at least one Nion, which will be communicating with up to 24 devices. Each additional Nion will add up to 24 additional devices. With all this traffic, there needs to be some type of rules to bring order to this chaos. Peavey Electronics ®2006 CobraNet Conductor Hence the CobraNet Conductor, which regulates all CobraNet devices, assigning a “time to send” to each device. This applies to all CABs, as well as the CobraNet cards in the Nions. The Conductor assignment is autonegotiated shortly after start-up for the CABs and Nions, with Nions having a higher priority than CABs. Peavey Electronics ®2006 CobraNet Conductor To understand how this works, let’s use a classroom analogy. If you had something to say, you could raise your hand and wait to be called. Of course this won’t work on a network. Peavey Electronics ®2006 CobraNet Conductor So lets says that as the instructor, I clap my hands once each 65 minutes (I know this sounds odd, but bear with me) and everyone has a clock that they lock to this signal. Peavey Electronics ®2006 CobraNet Conductor Now if we pre-arraigned that Joe would speak for 16 seconds on the beat. Then John would speak for 16 seconds at 16 seconds after (or offset from) the beat. Then Charlie would speak for 16 seconds at a offset of 32. Then Greg would speak for 16 seconds at a offset of 48. Then back to Joe for 16 seconds at a offset of 64 seconds after the beat. Peavey Electronics ®2006 CobraNet Conductor This is what the Conductor is doing. The Conductor sends the “beat” to which all nodes lock their clock. And then tells each node how much to offset from this beat to trigger the send. Peavey Electronics ®2006 CobraNet Conductor Now why did I use 65 minutes? Because this is what happens about every second on the network, and illustrates how much bandwidth is available. Peavey Electronics ®2006 CobraNet Conductor But what about other non-CobraNet nodes on a network? Collisions will not occur because we are using a switch, but if any other type of nodes that can’t listen to the Conductor are in use, other conflicts can occur. Peavey Electronics ®2006 CobraNet Conductor This is why we recommend a second switch (a physical network), or use a “managed switch” on which you can create VLANs (virtual networks), anytime you have much else on a network. Peavey Electronics ®2006 Packet Size Peavey Electronics ®2006 The Basic IEEE 802.3 MAC Data Frame Format The Data (and Pad as required) is an Explicit Length as defined by the Length/Type part of the Frame Peavey Electronics ®2006 Lower Latency We discussed explicit length as part of transport layer topic, remember the water hose and bucket. But let’s say that we use a smaller bucket, instead of a gallon bucket we use a half-gallon. So now we wait half as long to fill the bucket...Lower latency. So let’s now use a quart size bucket, half the size of the half-gallon. Again, lower latency. Peavey Electronics ®2006 Static IP Vs DHCP Peavey Electronics ®2006 DHCP Topics Define DHCP Define Static IP Show DHCP with a Alt. Config Static IP DHCP can assign IP Addresses via MAC address, but what happens when defective equipment is replaced. How can control equipment find replacement equipment. DHCP can assign IP addresses via “Friendly Names”, but friendly names not common in AV equipment. Nion can do both, and DHCP is helpful for initial set-up, but static IP is highly recommended for the finished install. Peavey Electronics ®2006 BroadCast MultiCast UniCast Peavey Electronics ®2006 Broadcast • By sending data to all possible destinations permits the sender to send the data only once, and all receivers can copy it. • A network broadcast in the IP protocol is done with 255.255.255.255, with a MAC address network, ff.ff.ff.ff.ff.ff is a broadcast. • Sub-net masking allows a directed (limited) broadcast can be made by combining the network prefix with the host suffix composed entirely of binary 1s. For example, to send to all addresses within a network with the prefix 192.0.2, the directed broadcast IP address is 192.0.2.255 (assuming the netmask is 255.255.255.0). Peavey Electronics ®2006 MultiCast • A multicast address is associated with a group of interested (subscribed) receivers. • IP addresses 224.0.0.0 to 239.255.255.255 are designated as multicast addresses. • The sender sends a single datagram (from the sender's unicast address) to the multicast address, and the routers take care of making copies and sending them to all receivers that have registered their interest in data from that sender. • Multicast packets are delivered by using the Ethernet MAC address range 01:00:5e:00:00:00 - 01:00:5e:7f:ff:ff Peavey Electronics ®2006 MultiCast • Switches that cannot understand multicast addresses will broadcast traffic sent to a multicast group to all the members of a LAN. In this case, the system's network card must filter the packets sent to multicast groups to which they are not subscribed. • There are a few switches that listen to multicast traffic, maintaining a table of which network nodes are subscribed to a given multicast group. This table is then used to forward traffic only to subscrbers. This is done through the use of IGMP Peavey Electronics ®2006 UniCast • The most common concept of an Ethernet address. • It normally refers to a single sender and a single receiver. • Usually, a unicast address (MAC or IP) is associated with a single device or host, but is not necessarily one-to-one correspondence. • Some individual NICs can have several distinct unicast (IP) addresses, each for its own distinct purpose. • Sending the same data to multiple unicast addresses requires the sender to send all the data many times over, once for each recipient. Peavey Electronics ®2006 Nion & CobraNet uses all three types (More info to come....) Peavey Electronics ®2006 Bundle Type Number 0 Null Bundle Numbering Usage Type Addressing Unused bundle. N/A Transmitted by a single 1-255 Multicast CobraNet device and Always multicast received by all other devices. Transmitted by a single CobraNet interface. Dependent on txUnicastMode Generally unicast and txMaxUnicast settings, but may multicast 256-65279 Unicast may be received at a single If txUnicastMode (default case), a few (multiple variable is adjusted unicast case), or a large number (multicast case) of interfaces. 65280Private Very Advanced 65535 Mode N/A Always Transmitted Only transmitted when at least one receiver is identified via reverse reservation Peavey Electronics ®2006 SNMP Peavey Electronics ®2006 Simple Network Management Protocol Background The Simple Network Management Protocol (SNMP) is an application layer protocol that facilitates the exchange of management information between network devices. Peavey Electronics ®2006 Simple Network Management Protocol It is part of the Transmission Control Protocol/Internet Protocol (TCP/IP) protocol suite. SNMP enables network administrators to manage network performance, find and solve network problems, and plan for network growth. Peavey Electronics ®2006 NETWORK MANAGEMENT: AD-HOC APPROACHES LOCAL SYSTEM - EXAMPLES: • PING • TRACEROUTE • NETSTAT • ... REMOTE SYSTEM • TELNET / RLOGIN (COMMAND LINE INTERFACE - CLI) • WEB INTERFACE EXAMPLES WEB INTERFACE: • PING • TRACEROUTE • WHOIS • NTOP Peavey Electronics ®2006 SNMP GOALS UBIQUITY • PCs AND CRAYs INCLUSION OF MANAGEMENT SHOULD BE INEXPENSIVE • SMALL CODE • LIMITED FUNCTIONALITY MANAGEMENT EXTENSIONS SHOULD BE POSSIBLE • NEW MIBs MANAGEMENT SHOULD BE ROBUST • CONNECTIONLESS TRANSPORT Peavey Electronics ®2006 Two versions of SNMP exist: SNMP version 1 (SNMPv1) and SNMP version 2 (SNMPv2). Both versions have a number of features in common, but SNMPv2 offers enhancements, such as additional protocol operations. Standardization of yet another version of SNMP—SNMP Version 3 (SNMPv3)— is just now available. Peavey Electronics ®2006 SNMP Basic Components An SNMP-managed network consists of three key components: managed devices, agents, and network-management systems (NMSs). Peavey Electronics ®2006 SNMP Basic Components A managed device is a network node that contains an SNMP agent and that resides on a managed network. Managed devices collect and store management information and make this information available to NMSs using SNMP. Managed devices, sometimes called network elements, can be routers and access servers, switches and bridges, hubs, computer hosts, or printers. Peavey Electronics ®2006 SNMP Basic Components An agent is a network-management software module that resides in a managed device. An agent has local knowledge of management information and translates that information into a form compatible with SNMP. Peavey Electronics ®2006 SNMP Basic Components An NMS executes applications that monitor and control managed devices. NMSs provide the bulk of the processing and memory resources required for network management. One or more NMSs must exist on any managed network. Peavey Electronics ®2006 SNMP Basic Components Managed devices are monitored and controlled using four basic SNMP commands: read, write, trap, and traversal operations. Peavey Electronics ®2006 SNMP Basic Components The read command is used by an NMS to monitor managed devices. The write command is used by an NMS to control managed devices. The trap command is used by managed devices to asynchronously report events to the NMS. Peavey Electronics ®2006 SNMP Basic Components Traversal operations are used by the NMS to determine which variables a managed device supports and to sequentially gather information in variable tables, such as a routing table. SNMP Management Information Base Peavey Electronics ®2006 A Management Information Base (MIB) is a collection of information that is organized hierarchically. MIBs are accessed using a networkmanagement protocol such as SNMP. They are comprised of managed objects and are identified by object identifiers. SNMP Management Information Base Peavey Electronics ®2006 A managed object (sometimes called a MIB object, an object, or a MIB) is one of any number of specific characteristics of a managed device. Managed objects are comprised of one or more object instances, which are essentially variables. SNMP Management Information Base Peavey Electronics ®2006 Two types of managed objects exist: scalar and tabular. Scalar objects define a single object instance. Tabular objects, define multiple related object instances that are grouped in MIB tables. Peavey Electronics ®2006 PRINCIPLE OPERATION MANAGER SNMP AGENTS MIB Peavey Electronics ®2006 PRINCIPLE OPERATION MANAGER POLLING TRAPS AGENTS MIB Peavey Electronics ®2006 PRINCIPLE OPERATION MANAGER GET / SET TRAP AGENTS MIB Peavey Electronics ®2006 PRINCIPLE OPERATION MANAGER AGENTS TABLES VARIABLES STANDARDS Peavey Electronics ®2006 SMI • STRUCTURE OF MANAGEMENT INFORMATION • RFC 1155 MIB-II • MANAGEMENT INFORMATION BASE • RFC 1213 • A LARGE NUMBER OF ADDITIONAL MIBs EXIST SNMP • SIMPLE NETWORK MANAGEMENT PROTOCOL • RFC 1157 • NAME IS USED IN A MORE GENERAL SENSE Peavey Electronics ®2006 SNMP Support MainFrames and MiniFrames Support SNMP v1 ONLY But could be upgraded to SNMP vX CobraNet supports SNMP v1 ONLY Nion supports SNMP v1 and v2 And SNMP v3 when available OKAY, why do I care about any of this? We will explain later when we talk about ControlManager Peavey Electronics ®2006 AV-IT CONVERGENCE BUT I DON’T WANT TO CONVERGE!!! Peavey Electronics ®2006