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Configuration Guide

Peter Brightwell edited this page Aug 17, 2018 · 9 revisions

As far as possible, the NMOS specifications make use of automated configuration techniques. Where additional configuration is required this will typically be carried out according to vendor-specific instructions (for example when configuring manual IP addressing). The following examples provide details for configuring aspects of systems which are agnostic to specific implementations.

DNS Server Configuration

Unicast DNS provides a more scalable discovery solution for APIs which make use of DNS-SD, as opposed to multicast DNS. Any standard DNS server will support the ability to advertise DNS-SD services. The following example shows how to configure a Linux Bind DNS server to advertise an IS-04 Registration and Query API, but similar configuration can be applied to other popular server implementations.

; These lines indicate to clients that this server supports DNS Service Discovery
b._dns-sd._udp	IN	PTR	@
lb._dns-sd._udp	IN	PTR	@

; These lines indicate to clients which service types this server may advertise
_services._dns-sd._udp	PTR	_nmos-registration._tcp
_services._dns-sd._udp	PTR	_nmos-query._tcp

; These lines give the fully qualified DNS names to the IP addresses of the hosts which we'd like to discover
; This example uses a domain of 'dns.nmos.tv'. We recommend using a subdomain of a domain name which you own.
registration1.dns.nmos.tv.	IN	A	192.168.200.5
query1.dns.nmos.tv.	IN	A	192.168.200.6

; There should be one PTR record for each instance of the service you wish to advertise.
; Here we have one Registration API (_nmos-registration._tcp) and one Query API (_nmos-query._tcp)
_nmos-registration._tcp	PTR	reg-api-1._nmos-registration._tcp
_nmos-query._tcp	PTR	qry-api-1._nmos-query._tcp

; Next we have a SRV and a TXT record corresponding to each PTR above, first the Registration API
; The SRV links the PTR name to a resolvable DNS name (see the A records above) and identify the port which the API runs on
; The TXT records indicate additional metadata relevant to the IS-04 spec
reg-api-1._nmos-registration._tcp	SRV	0 0 80 registration1.dns.nmos.tv.
reg-api-1._nmos-registration._tcp	TXT	"api_ver=v1.0,v1.1,v1.2" "api_proto=http" "pri=0"

; Finally, the SRV and TXT for the Query API
qry-api-1._nmos-query._tcp	SRV	0 0 80 query1.dns.nmos.tv.
qry-api-1._nmos-query._tcp	TXT	"api_ver=v1.0,v1.1,v1.2" "api_proto=http" "pri=0"
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