iCap uses a relatively small amount of bandwidth per stream, but needs to have access to that bandwidth very reliably in order to see optimal performance.
When customers have a problem with iCap audio quality, most commonly the issue is with short-term bouts of packet latency or poor connection quality related to other software or devices temporarily congesting the network. Many common applications, especially ones that transfer large files, have a "bursty" usage profile, and this can cause temporary and unpredictable problems for more real-time applications like iCap.
In a larger managed network, implementing a form of QoS for traffic from iCap encoders may be a good idea to ensure optimal service.