Common Issues

The following issues have been noted at workshop events and are recorded here in the hope that they will save some time in debugging.

DNS-SD

• Multicast DNS response messages consist of a PTR, SRV, TXT and A/AAAA record. In some implementations these may arrive in one packet. In others they may arrive in separate packets. mDNS browsers should be able to handle all of these cases.
• The '_nmos-registration._tcp' IS-04 service type breaches the length constraints imposed by the RFC, which can cause issues for some clients. The '_nmos-register._tcp' service type is used from v1.3 in order to overcome this, and can be used for earlier versioned Nodes where they have been upgraded to support it.

HTTP APIs

• An 'Access-Control-Allow-Origin' header must be returned with every single response to any API request. This includes basic requests such as GET and HEAD.
• A full set of CORS headers must be returned with responses to OPTIONS requests, and with responses to HTTP methods which may modify the resource (such as POST, PUT, PATCH, DELETE etc).
• APIs may advertise URLs with or without a trailing slash. Clients should exercise care when appending additional paths to these URLs.