- Application Note...
Ethernet Switches and ServSwitch Agility KVM-over-IP Extension
The important interoperability considerations when choosing Ethernet switches for use with Agility systems. (Version 1)
Black Box Explains...Multicasting video over a LAN: Use the right switch.
Product Data Sheets (pdf)...ServSwitch Agility
In KVM extension applications where you want to distribute HD video across a network, you need to understand how it works and what kind of networking equipment to use with... more/see it nowyour extenders.
Think of your network as a river of data with a steady current of data moving smoothly down the channel. All your network users are like tiny tributaries branching off this river, taking only as much water (bandwidth) as they need to process data. When you start to multicast video, data, and audio over the LAN, those streams suddenly become the size of the main river. Each user is then basically flooded with data and it becomes difficult or impossible to do any other tasks. This scenario of sending transmissions to every user on the network is called broadcasting, and it slows down the network to a trickle. There are network protocol methods that alleviate this problem, but it depends on the network switch you use.
Unicast vs. multicasting, and why a typical Layer 2 switch isn’t sufficient.
Unicasting is sending data from one network device to another (point to point); in a typical unicast network, Layer 2 switches easily support these types of communications. But multicasting is transmitting data from one network device to multiple users. When multicasting with Layer 2 switches, all attached devices receive the packets, whether they want them or not. Because a multicast header does NOT have a destination IP address, an average network switch (a Layer 2 switch without supported capabilities) will not know what to do with it. So the switch sends the packet out to every network port on all attached devices. When the client or network interface card (NIC) receives the packet, it analyzes it and discards it if not wanted.
The solution: a Layer 3 switch with IGMPv2 or IGMPv3 and packet forwarding.
Multicasting with Layer 3 switches is much more efficient than with Layer 2 switches because it identifies the multicast packet and sends it only to the intended receivers. A Layer 2 switch sends the multicast packets to every device and, If there are many sources, the network will slow down because of all the traffic. And, without IGMPv2 or IGMPv3 snooping support, the switch can handle only a few devices sending multicasting packets.
Layer 3 switches with IGMP support, however, “know” who wants to receive the multicast packet and who doesn’t. When a receiving device wants to tap into a multicasting stream, it responds to the multicast broadcast with an IGMP report, the equivalent of saying, “I want to connect to this stream.” The report is only sent in the first cycle, initializing the connection between the stream and receiving device. If the device was previously connected to the stream, it sends a grafting request for removing the temporary block on the unicast routing table. The switch can then send the multicast packets to newly connected members of the multicast group.
Then, when a device no longer wants to receive the multicast packets, it sends a pruning request to the IGMP-supported switch, which temporarily removes the device from the multicast group and stream.
Therefore, for multicasting, use routers or Layer 3 switches that support the IGMP protocol. Without this support, your network devices will be receiving so many multicasting packets, they will not be able to communicate with other devices using different protocols, such as FTP. Plus, a feature-rich, IGMP-supported Layer 3 switch gives you the bandwidth control needed to send video from multiple sources over a LAN.
Broadcast and Media Solutions
Enabling next-generation connectivity solutions for broadcast and media professionals.
ServSwitch Agility Controller Unit API Manual
API Manual for the ACR1000A-CTL (Version 2)
Video...AV-Over-IP Webinar from Black Box
Sending high-quality images and video over a local area network (LAN) has never been easier or more advantageous. It's cost-effective, easy to implement, flexible and scalable, and has no distance... more/see it nowlimitations. Using an IP-based video distribution platform, such as the MediaCento™ IPX, provides a whole new level of scalability compared to existing proprietary and coax systems. Any number of displays located anywhere in the building can receive video content through connection to the LAN. In addition to AV-over-IP solutions such as the MediaCento IPX, Black Box has a host of ProAV solutions, such as HDMI matrix switches, scalers, and video wall controllers collapse
ServSwitch Agility Controller Unit Firmware
Firmware for the ACR10000A-CTL (Version 2.4.21075)
Digital KVM extension and switching over IP.
ServSwitch Agility DVI, USB, and Audio Extenders over IP User Manual
User Manual for the ACR1000A, ACR1000A-T, ACR1000A-R, ACR1002A, ACR1002A-T, and ACR1002A-R (Version v2-0d)
ServSwitch Agility Dual DVI, USB, and Audio KVM Extender over IP (Dual-Head or Dual-Link) Firmware
Firmware for the ACR1002A-T and ACR1002A-R (Version 2.9.21660)