Chapter 13 – Optimizing Your Network Design.docx

12 Pages
Unlock Document

Information Technology Management
ITM 600
Robert Hudyma

Chapter 13Optimizing Your Network DesignOptimization is a critical design step for organization that highbandwidth and delay sensitive applicationsOptimizing Bandwidth Usage with IP Multicast TechnologiesOne of the main reasons optimization techniques are required on internetworks is the increasing use of highbandwidth multipleuser multimedia applicationsoSuch as video conferencing collaborative computing and distance learningThe IETF has developed several IP multicast standards that optimize the transmission of multimedia and other types of traffic across an internetworkOlder multimedia application use a unicast pointtopoint method of handling multimedia traffic that wastes bandwidth or send a single stream and use a broadcast destination addressoDisadvantage data stream goes to all devices even devices for which no application is installed to handle the streamIP multicast technologies can be used by universities businesses and other organizations and computersimulation applicationsIP Multicast AddressingIP multicasting transmits IP data to a group of hosts that is identified by a single Class D IP addressohost group addresses range from 224000 to 239255255255Network stations recognize an address as being a Class D address because the first 4 bits must be 1110 in binaryA multicast group is also identified by a MAC layer multicast addressThe Internet Assigned Numbers Authority IANA owns a block of MAC layer addresses that are used for group multicast addressesThe range of addresses for Ethernet is 01005E000000 to 01005E7FFFFFWhen a station sends a frame to an IP group that is identified by a Class D address the station inserts the loworder 23 bits of the Class D address into the loworder 23 bits of the MAC layer destination address The top 9 bits of the Class D address are not used The top 25 bits of the MAC address are 01005E followed by a 0 or in binary the following o00000001 00000000 01011110 0MAC addresses are written in hexadecimal whereas IP addresses are written in dotted decimal notationInternet Group Management ProtocolInternet Group Management Protocol IGMP enables a host to join a group and inform routers of the need to receive a particular data streamWhen a user that requires a host to join a multicast group the host transmits a membership report message to inform routers on the segment that traffic for the group should be multicast to the host s segmentIGMP specifics that a multicast routers sends an IGMP query out every interface at regular intervals to see if any hosts belong to the groupoHost responds with a IGMP membership message for each groupoIt only need to recognize that a group has aleast one member on a segmentHosts set a random timer before responding to queries The Cisco Group Management Protocol CGMP and the IETF IGMP snooping methods allow switches to participate in the process of determining which segments have hosts in a particular multicast groupMulticast Routing ProtocolsA router must also learn how to route multicast traffic across an internetwork multicast routing protocol provides this functionWhereas a standard unicast routing protocol learns paths to destination networks a multicast routing protocol learns paths to multicast destination addresses Multicast routing protocols help routers learn which interfaces should send each multicast stream There are two multicast routing protocols Distance Vector Multicast Routing Protocol DVMRP and Protocol Independent Multicast PIMDistance Vector Multicast Routing ProtocolDVMRP was based on the unicast Routing Information Protocol RIPDVMRP was an Interior gateway protocol IGP suitable for use within an autonomous system AS but not between different autonomous systemsThe key difference between RIP and DVMRP is that RIP learns the path to a particular destination whereas DVMRP keeps track of the return paths to the source of multicast packetsDVMRP combines many of the features of RIP with the Truncated Reverse Path Broadcasting TRPB algorithmoEach multicast router determines its place in the tree relative to the particular source and then determines which of its interfaces are in the shortest path tree
More Less

Related notes for ITM 600

Log In


Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.