Explains about Layer 2 and Layer 3 Multicast technologies

1. Multicast Solution How does it work ? Hit left mouse key, the Enter key or Page Up or Down to advance to the next slide July 2005 version 3

3. Typical Network Requirements Monitor any video from anywhere in the network Backbone

17. Layer 2 Switch Functionality L2 Switch L2 Switch Decoder Decoder 5 Mbps 15 Mbps 5 Mbps 15 Mbps 5 Mbps 15 Mbps 5 Mbps 15 Mbps 0 Mbps 20 Mbps 0 Mbps 20 Mbps The combined Multicast Traffic is sent to all ports in each Switch This is a valid network topology for small networks Ensure no more then 70% of the bandwidth of the lowest negotiated Ethernet port speed is used. Not to be used with 10 Meg Half Duplex devices. Bandwidth Restriction applies. 5 Mbps Multicast Video per Encoder 20 Mbps Encoder Encoder Encoder Encoder Combined 20 Mbps Multicast Video Traffic

18. Layer 3 Switch/Router with IGMP Functionality L3 Switch L3 Switch Decoder Decoder 5 Meg 5 Meg 5 Meg 5 Meg 5 Meg Multicast traffic is filtered out at each switch Only the required traffic is transmitted on the network This is a valid network topology for any network - No topology restrictions 10 Mbps Deploying a Layer 3 at each collector HUB could be expensive 5 Mbps 0 Mbps 5 Mbps 0 Mbps 5 Mbps 0 Mbps 5 Mbps 0 Mbps 0 Mbps 0 Mbps 5 Mbps 5 Mbps Encoder Encoder Encoder Encoder Combined 10 Mbps Multicast Video Traffic

19. Layer 2 & 3 Switch Typical Topology Decoder Decoder 0 Mbps 0 Mbps The L3 Switch controls all Multicast traffic. In and out. It eliminates transmitting the combined multicast traffic unnecessarily to each port. 0 Mbps L3 Switch The use of L2 Switch in this topology is very common. Multicast traffic is repeated on all ports of the switch within the segment but traffic from other segments is not seen. Traffic between the segments is controlled by the L3 switch. Economical and practical solution that is very easy to deploy. 35 Mbps Combined Multicast Video 35 Mbps Combined Multicast Video 5 Mbps L2 Switch Encoder L2 Switch Encoder L2 Switch Encoder L2 Switch Encoder L2 Switch Encoder L2 Switch Encoder L2 Switch Encoder L2 Switch Encoder L2 Switch Encoder L2 Switch Encoder L2 Switch Encoder L2 Switch Encoder L2 Switch Encoder L2 Switch Encoder 5 Mbps

21. Overview of OSI Model Application Presentation Session Transport Network Data Link Physical Layer 7. Layer 6 Layer 5 Layer 4 Layer 3- This layer defines the addressing and routing structure of the Inter-network This layer controls the Multicast traffic on the network. Layer 2- This layer defines the framing, addressing and error control of Ethernet packets. Port addressing uses MAC address of each device. This layer effectively treats Multicast traffic as broadcast traffic. Layer 1 Traditionally performed by Routers Performed by Switches $ $

22. Overview of OSI Model Network Data Link $ $ New product introduced $ Layer 2 with IGMP Snooping - Layer 2 Switches with IGMP Snooping functionality are now available. Provide all the functionality of a Layer 2 switch with PARTIAL IGMP support. This layer provides some Multicast traffic control on the network. This product can be used instead of expensive Routers Available with different port densities. 100Base-Fx to Gigabit trunks. Temperature Hardened Wide choice of manufacturers and products. Layer 3- This layer defines the addressing and routing structure of the Inter-network This layer controls the Multicast traffic on the network. Layer 2- This layer defines the framing, addressing and error control of Ethernet packets. Port addressing uses MAC address of each device. This layer effectively treats Multicast traffic as broadcast traffic.

23. Layer 2 Switch with IGMP Snooping Functionality L2 with IGMP Snooping L3 Switch Decoder Decoder Valid network topology for any network No topology restrictions Local traffic is filtered out at each switch. Eliminates multicasts traffic to all the ports All the multicast traffic is sent to the central site. The L3 switch still controls the IGMP table of the network. 5 Mbps 0 Mbps 5 Mbps 0 Mbps 20 Mbps Combined Multicast Video Encoder Encoder Encoder Encoder 5 Mbps 0 Mbps 5 Mbps 0 Mbps 5 Mbps 0 Mbps 5 Mbps 0 Mbps

24. L2 with Snooping & L3 Switch Typical Topology Decoder Decoder 0 Mbps 5 Mbps 0 Mbps 5 Mbps L2 Switch Encoder L2 Switch Encoder L2 Switch Encoder L2 Switch Encoder L2 Switch Encoder L2 Switch Encoder L2 Switch Encoder L2 Switch Encoder L2 Switch Encoder L2 Switch Encoder L2 Switch Encoder L2 Switch Encoder L2 Switch Encoder L2 Switch Encoder These links contain the combined Multicast traffic from all the Encoders in their segment i.e. 35 Mbps. L3 Switch Very practical implementation Management of the Ethernet Switches is required. Switches with IGMP Snooping eliminate flooding local interfaces with Multicast traffic. Bandwidth Restriction applies. No more “70% of link capacity” 35 Mbps 35 Mbps

25. How does it work? From the Encoder to the L3 Switch Decoder L2 Switch Encoder L2 Switch Encoder L2 Switch Encoder L2 Switch Encoder L2 Switch Encoder L2 Switch Encoder L2 Switch Encoder The L3 Switch forwards the IGMP Query on all its ports to determine if there are any devices that wish to subscribe to a Multicast Group. 0 Mbps L3 Switch Each Encoder forwards a constant Multicast stream to the Ethernet Switch (224-239.x.x.x) The L2 Switch detects/identifies the Multicast stream source and logs internally what port this stream came from. The L2 Switch with IGMP Snooping detects the Query message from the L3 Switch and logs internally the ports that pass traffic to the L3 Switch L2 Switch eliminates flooding of the local interfaces and passes the Multicast traffic to the L3 Switch for processing. 0 Mbps 5 Mbps 35 Mbps

26. How does it work? From the Encoder to the L3 Switch Decoder 0 Mbps L2 Switch Encoder L2 Switch Encoder L2 Switch Encoder L2 Switch Encoder L2 Switch Encoder L2 Switch Encoder L2 Switch Encoder The L3 Switch detects the Multicast traffic arriving on this interface and logs internally all the Multicast address for distribution. 0 Mbps L3 Switch At this point, the Multicast traffic from all Encoders is combined on this link towards the L3 Switch. 35 Mbps Combined Multicast Traffic 5 Mbps

29. How does it work? Typical Star Topology Decoders Multicast traffic flows from all Encoders to the L3 Switch L3 Switch controls the distribution of all Multicast traffic to Decoders Encoder L2 Switch with IGMP Snooping L3 Switch

30. Watch for… Limitations of IGMP Snooping Decoder L2 Switch Encoder L2 Switch Encoder L2 Switch Encoder L2 Switch Encoder L2 Switch Encoder L2 Switch Encoder L2 Switch Encoder L3 Switch L2 Switches with IGMP Snooping have limitations. In the event of a communication break between the L2 and L3 switches, the L2 IGMP Snooping switch will behave like a L2 switch A few minutes after loss of signal, the switches may* flood all Multicast signals to the ports of every switch * Behavior may differ depending on switch manufacturer. If this is a Gig E link and you have more then 70 Meg of Video traffic, no other application will run on this network until the link is re-established. Maximum port traffic will be exceeded.

31. Watch for… Distributed Control Centers Decoder Decoder Control Center # 2 Decoder Decoder Control Center # 1 Multicast traffic flows to the L3 Switch Multicast “join” request sent to the L3 Switch This switch will allow traffic from network A to flow to the Decoder when a “join” request is received. Video Source A Network A L2 Snooping Encoder L3 Switch Encoder L2 Snooping

32. Watch for… Distributed Control Centers Decoder Decoder Control Center # 2 Decoder Decoder Control Center # 1 This switch requires connectivity to the L3 switch to provide local “join” It will not be possible to view any video. Not even local video. Communication break This limitation can be eliminated by installing an L3 Switch at all Control Centers. Video Source A Network A L2 Snooping Encoder L3 Switch Encoder L2 Snooping

33. Watch for… Distributed Control Centers Decoder Decoder Control Center # 2 Decoder Decoder Control Center # 1 Video Source A Video Source B L2 Snooping Encoder L3 Switch Encoder L2 Snooping L2 Snooping Encoder Encoder All Multicast traffic will flow to the L3 Switch Multicast traffic flows to the L3 Switch This switch will only forward traffic from video source B when the Decoder requests to join a video from source B Multicast “join” requests are sent to the L3 Switch

34. Configuration Tips L2 Switch with IGMP Snooping Decoder Decoder Control Center # 2 Decoder Decoder Control Center # 1 Two IGMP configuration modes can be set in the switches. Passive Passive Passive This switch generates IGMP Queries. It is considered as the “Master” or the “Active” device In this topology, there can only be one Master unit. L2 Snooping Encoder L3 Switch Encoder L2 Snooping L2 Snooping Encoder Encoder

35. Configuration Tips L2 Switch with IGMP Snooping Decoder Decoder Control Center # 2 Decoder Decoder Control Center # 1 Some L2 Switches with IGMP Snooping can be configured as Passive or Active Passive Passive Passive This switch generates IGMP Queries. It is considered as the “Master” or the “Active” device In this topology, there can only be one Master unit. This topology should only be considered for small networks. Most L2 IGMP Snooping Switches do not have the capacity to handle a large table of IGMP Multicast traffic. L2 Snooping Encoder Encoder L2 Snooping L2 Snooping Encoder Encoder L2 Snooping

36. Multi-Vendor Support Avoid…Mixing IGMP Snooping Switches Decoder Decoder Control Center # 2 Decoder Decoder Control Center # 1 Passive Passive Passive Although some L2 IGMP Snooping Switch manufacturers may imply that they can integrate into a multi-vendor solution, this is not recommended since IGMP Snooping is not an RFC standard. Implementation differs between manufacturers. (Proven to fail in our labs) Active Manufacturer A Manufacturer A Manufacturer B Manufacturer B L2 Snooping Encoder Encoder L2 Snooping L2 Snooping Encoder Encoder L2 Snooping

37. Multi-Vendor Support Recommendation … Decoder L3 Switch High end products should be used for L3 Switch to control all your Multicast traffic. Products from Foundry , Extreme, Nortel and Cisco (to name just a few) should be used. These are typically non-hardened products Use L2 with IGMP Snooping “ Hardened” products are available Keep it simple. A single manufacturer solution is recommended Several vendors offer a wide range of products for this application. Several (including Magnum 6Ks from GarrettCom) were tested at iMPath with positive results. L2 Switch Encoder L2 Switch Encoder L2 Switch Encoder L2 Switch Encoder L2 Switch Encoder L2 Switch Encoder L2 Switch Encoder

38. Multi-Vendor Support Avoid… Decoder L3 Switch Do not MIX different vendors IGMP Snooping switches in this topology. It will most-likely not work Manufacturer A Manufacturer A Manufacturer A Manufacturer A Manufacturer A Manufacturer B Manufacturer B Although some L2 IGMP Snooping Switch vendors may suggest they can integrate into a multi-vendor solution, this is not recommended since IGMP Snooping is not a RFC standard. Implementation differs between manufacturers. (Proven to fail in our labs) L2 Switch Encoder L2 Switch Encoder L2 Switch Encoder L2 Switch Encoder L2 Switch Encoder L2 Switch Encoder L2 Switch Encoder

39. Multi-Vendor Support Recommendation… Decoder When multi-vendor solutions are used, it is recommended to use a single manufacturer solution on each link. Use the L3 Switch to separate each group (manufacturer) of L2 IGMP switches. This is the most reliable topology to support multi-vendor solutions. Manufacturer B Manufacturer C Manufacturer A Manufacturer A Manufacturer B Manufacturer C L3 Switch