User guide
12 HYDRA2 Operator Manual
Introduction - Hydra2 Networking
MULTI-CONSOLE NETWORKS
Routers from different processing 
racks can be connected together. 
Networking consoles in this way 
gives access to all I/O from all control 
surfaces and system PCs on the 
same Hydra2 network.
Each console’s access to I/O can be 
managed from the Hydra2 Organizer 
(H2O). Individual consoles can be denied 
access to I/O by groups of I/O boxes, 
specific I/O boxes, specific ports, or 
groups of ports.
Inputs can be used simultaneously by 
multiple consoles on the same network. 
Any console with access can patch audio 
to any of its DSP inputs and to any output 
ports.
Router to router connections, like I/O 
boxes, can be made using any of the 
16 front panel Hydra2 router ports. 
Connecting racks together creates 
multiple linked star formations, as shown 
in Figure 1. All 3 routers shown have 
access to all of the I/O shown. The path 
from I/O box to console may pass through 
multiple router cards before reaching the 
console’s own router.
It is important that there is only one path 
between any two points in the network 
(not counting secondary paths designed 
for redundancy, or configured trunks for 
increased bandwidth). Having multiple 
paths between two points will cause 
data collisions and instability. Figure 2 
shows an incorrect connection of three 
processing racks. The addition of a third 
router-to-router link creates a duplicate 
path. The route between any two 
processing racks can be direct or via the 
other processing rack. Removing any one 
of the three marked links will correct the 
problem.
When connecting two or more routers 
together it is important that one of 
them, and only one, is configured to 
be the Master Router.
Please see the Master Router section of 
this document for more details.
It is also important to the ensure IP 
address compatibility of the systems 
being connected together.
Please see the IP Address management 
section of this document for more details.
FIGURE 1 - CORRECT CONNECTION OF A THREE STAR FORMATION NETWORK
Router / 
Processing 
Rack
Audio I/O Audio I/O
Audio I/OAudio I/O
Router / 
Processing 
Rack
Audio I/O Audio I/O
Audio I/OAudio I/O
Router / 
Processing 
Rack
Audio I/O Audio I/O
Audio I/OAudio I/O
Three router racks connected with no duplicate paths.
Router / 
Processing 
Rack
Audio I/O Audio I/O
Audio I/OAudio I/O
Router / 
Processing 
Rack
Audio I/O Audio I/O
Audio I/OAudio I/O
Router / 
Processing 
Rack
Audio I/O Audio I/O
Audio I/OAudio I/O
FIGURE 2 - INCORRECT CONNECTION OF A THREE STAR FORMATION NETWORK
Incorrect Connection The additional link creates duplicate paths.
Each Hydra2 link is capable of carrying up 
to 512 channels of audio simultaneously 
in each direction. This imposes no 
limitations over I/O box to router 
connections as no single I/O box contains 
more than 512 input or output ports.
It is important however in multi-rack 
systems to understand the network 
topology; a single connection between 
two routers is also limited to 512 channels 
in each direction. This imposes a limit on 
the amount of I/O that can be accessed 
via other routers’ connections at any 
given time. The bandwidth available is 










