The redundancy function works on LAN only i.e. all units must be in the same IP broadcast range. A max. of 254 devices is supported.

Transcription

1 IP Audio Interface Redundant network connection PRS-1AIP1 1. Introduction This application note (AN) describes how to have a redundant Ethernet network connection for the PRS- 1AIP1, IP Audio Interface. 1.1 The IP Audio Interface The PRS-1AIP1, IP Audio Interface, is a universal, IP based audio device supporting Audio over IP applications. It is used for bridging audio and contact closures over long distance LAN and WAN networks. It extends and interfaces to e.g. Praesideo and non network based, traditional, public address systems, like Plena, without the need for a PC during operation. Some product features: - Digital audio transmission between PA systems on remote locations. - Designed to comply to Voice Evacuation standards - Supervised control inputs and control outputs - Configuration via a web browser 1.2 General In a lot of applications a single Ethernet connection between the IP Audio Interface and the Ethernet network is sufficient. Redundancy is not always required due to the nature of the project. In applications where a high degree of redundancy is required, the IP Audio Interface can have a redundant network connection. The redundancy function works on LAN only i.e. all units must be in the same IP broadcast range. A max. of 254 devices is supported. This Application Note will give some examples of how to get a redundant Ethernet connection for the IP Audio Interface. The web pages are always available via either Ethernet connection. Upgrading the IP Audio interface SW is only possible via connection Ethernet Abbreviations AN VLAN Application Note IP Audio Interface Virtual Local Area Network PRS-1AIP AN IP Audio interface, Redundant network connection 1-5

2 2. Network connection on the IP Audio Interface The PRS-1AIP1 has 2 Ethernet connections. Both connections have the same IP address and the same MAC address. 2.1 IP address The IP address of the IP Audio interface, set on the configuration page, is used for both network connections. Because it is not allowed to have 2 units with identical IP address connected to the same Ethernet, both Ethernet connection should never be connected to the same Ethernet. 3. Connection to an Ethernet network When only a single network connection is required Ethernet 1 should always be used. With this setup there will be no redundancy. When the connection to the Ethernet network is lost there will be no data stream received by the receiving unit. Supervision When in the configuration of the receiving unit the Supervision sensor Stream Loss is set to Local Fault the fault relay on this unit will be activated when the data stream of the transmitting is lost AN IP Audio interface, Redundant network connection 2-5

3 3. Connection to an Ethernet network with redundancy There are 2 ways of having a redundant network connection: 3.1 Two separate Ethernet networks. Connect Ethernet 1 to the 1st Ethernet network and connect Ethernet 2 to the 2 nd Ethernet network. This way there is a 100% separation of networks. Both networks will have the same data stream from one unit to the other. The receiving unit will select with one to use. In case one of the connections to the Ethernet is lost the receiving unit will automatically use the data stream from the remaining network. - Make sure that the 2 separate Ethernet s are never connected. This would result in a complete collapse of the system. - The timing in both Ethernet networks should be the same i.e. similar HW should be used in both networks. Also, no other data should be on the network. 3.2 Supervision: When, in the configuration of the receiving unit, the Supervision sensor Stream Loss is set to Local Fault, the fault relay on this unit will be activated when the data stream, received from the transmitting unit, is lost. Keep in mind that this fault is generated only when the data stream on both Ethernet 1 and Ethernet 2 is lost AN IP Audio interface, Redundant network connection 3-5

4 3.3 2 VLAN s on a single Ethernet network An alternative for two separate Ethernet network is to use a single network but, virtually, split the network in two separate networks. The result of this are two VLAN s on one network. The two, virtual, networks exist on one network without seeing each other. Communication between the two networks is not possible inside the switch. Keep in mind that using VLAN doesn t give you a redundant Ethernet network but a redundant connection between the IP Audio interface and the Ethernet network. To achieve a full redundant Ethernet network you have to use separate networks. In the block diagram above you see port 1 6 assigned to VLAN 1 and port 7 12 assigned to VLAN 2. Communication between the 2 VLAN s is not possible. The VLAN s also exists on the connection between the switches, however, they have to share the available bandwidth of the connection. To be able to create a VLAN the switches have to be Managed switches. Unmanaged switches cannot create a VLAN. Check the manual of the switch how to create the VLAN Redundant IP Audio Interface connection Using the VLAN as described before, the two network connections of the IP Audio Interface can each be connected to there own, VLAN, network. Because the 2 VLAN s are completely separated even the double IP addresses can exist in the network AN IP Audio interface, Redundant network connection 4-5

5 Supervision: When, in the configuration of the receiving unit, the Supervision sensor Stream Loss is set to Local Fault, the fault relay on this unit will be activated when the data stream, received from the transmitting unit, is lost. Keep in mind that this fault is generated only when the data stream on both Ethernet 1 and Ethernet 2 is lost. 4. Behavior of the IP Audio interface when one of the network connections is lost Basically the transmitter is always transmitting a data stream on both connections Ethernet 1 and Ethernet 2. The receiving units is always receiving the data stream on Ethernet 1 When the connection to Ethernet 2 is lost the unit will continue receiving the data stream of the Ethernet 1 connection. When the Supervision sensor Stream Loss on the receiving unit is set to Local fault there will be no fault indication in the unit. When the connection to Ethernet 1 is lost the receiving units will automatically use the data stream of the Ethernet 2 connection. The switch over is hardly audible. Also here, when the Supervision sensor Stream Loss on the receiving unit is set to Local fault there will be no fault indication in the unit AN IP Audio interface, Redundant network connection 5-5