BT ITS recording network and server requirements

Owned by Kiss, Mate
Feb 26, 2024
2 min read

BT ITS recording has very specific requirements for the network. Below you can find the key requirements. For more detailed information, contact your BT representative.

  • One-way network delay between IP Voice Recorders and the IPSI should not exceed 400ms on a LAN or WAN. Delays of more than this will affect the ability to link CTI data with Vox segments.
  • Network jitter on the same path should not exceed 20ms on LAN or WAN.
  • Separate Network connections for N+1 deployments and use separate NICs for Management, IPSI LAN A and IPSI LAN B. NIC teaming is not supported and it is mandatory to use separate physical network connections for the VM hosts. In the case of 2N recording, use a separate NIC for the ITS voice traffic and another NIC for everything else.
  • Sufficient network bandwidth must be provided for the number of TTPs and Management traffic. Since TTPs do not use a VAD codec, silence is always present and therefore a continuous 32 channel voice stream for each TTP. This will occupy around 2.6 Meg of bandwidth on an IP network. The TTP packets will be QOS marked as EF by default and will need to be treated as Class 1 voice by the network.
  • Minimal network hops: the factory default IPSI heartbeat TTP Voice LAN settings are required to ensure reliable voice delivery and it is not recommended they be adjusted. 
  • NetBIOS must be disabled on all LANs that the recorder components are connected to, except the Management LAN. Specifically, this means the Voice LAN. The reason for this is that server names would be resolved on the Voice LAN and that would break the fault-tolerant model, i.e., when Management LAN cable is removed, the Unified Recorder or Director is still accessible via the Voice LAN. Access Control Lists (ACLs) might need to be put in place to prevent this. No Default Gateway must be configured for any recorder Voice LAN NICs.
  • Maximum 64 TTPs can be allocated to a single recorder. The system is distributing the TTPs across the Media Recorders evenly by default. The system can be configured to assign specific TTPs to specific Media Recorders. In either case, a single Media Recorder will be only assigned to maximum 64 TTPs by the Recording Director.