The MX field in an SSDP (Simple Service Discovery Protocol) message is used to specify the maximum number of seconds that a device should wait before responding to the message. It is used in M-SEARCH messages to request that devices search for and return information about available services. In the code you provided, the MX field is set to 3, which means that devices should wait a maximum of 3 seconds before responding to the M-SEARCH messag The MAN field in the M-SEARCH message is an HTTP header field that specifies the type of the message. In this case, it is set to "ssdp:discover"
M-SEARCH * HTTP/1.1 HOST: 239.255.255.250:1900 MAN: "ssdp:discover" MX: seconds to delay response ST: search target USER-AGENT: OS/version UPnP/1.1 product/version
MAN REQUIRED by HTTP Extension Framework. Unlike the NTS and ST field values, the field value of the MAN header field is enclosed in double quotes; it defines the scope (namespace) of the extension. MUST be "ssdp:discover".
MX REQUIRED. Field value contains maximum wait time in seconds. MUST be greater than or equal to 1 and SHOULD be less than 5 inclusive.
ST REQUIRED. Field value contains Search Target. MUST be one of the following. (See NT header field in NOTIFY with ssdp:alive above.) Single URI.
ssdp:all => Search for all devices and services.
upnp:rootdevice => Search for root devices only.
uuid:device-UUID => Search for a particular device. device-UUID specified by UPnP vendor.
urn:schemas-upnp-org:device:deviceType:ver => Search for any device of this type where deviceType and ver
are defined by the UPnP Forum working committee.
urn:schemas-upnp-org:service:serviceType:ver => Search for any service of this type where serviceType and ver
are defined by the UPnP Forum working committee.
urn:domain-name:device:deviceType:ver => Search for any device of this typewhere domain-name (a Vendor Domain Name),
deviceType and ver are defined by the UPnP vendor and ver specifies the highest specifies the highest supported version
of the device type. Period characters in the Vendor Domain Name MUST be replaced with hyphens in accordance with
RFC 2141.
urn:domain-name:service:serviceType:ver => Search for any service of this type. Where domain-name
(a Vendor Domain Name), serviceType and ver are defined by the UPnP vendor and ver specifies the highest specifies
the highest supported version of the service type. Period characters in the Vendor Domain Name MUST be replaced
with hyphens in accordance with RFC 2141.
WANPPPConnection
PPP connections originating at the gateway or relayed or bridged through the gateway
WANIPConnection IP connections originating or relayed or bridged through the gateway
WANPOTSLinkConfig Configuration parameters associated with a WAN link on a Plain Old Telephone Service (POTS) modem
WANDSLLinkConfig Configuration parameters associated with a WAN link on a Digital Subscriber Link (DSL) modem
WANCableLinkConfig Configuration parameters associated with a WAN link on a cable modem
WANEthernetLinkConfig Configuration parameters associated with an Ethernet- attached external modem (cable or DSL). If proprietary mechanisms are available to discover and configure an external modem, it is recommended that modem-specific LinkConfig services be modeled instead of this service
Starts the inets ( httpc(HTTP/1.1 client , httpd HTTP server API ) application. Opens the port 0 and sets the options [:active, :inet, :binary] for the socket. Sends the M-SEARCH request to the multicast address St: defines server tyype for IGD:1 discovery. Gen.udp: is used as a transport protocol for socket.
An Internet Gateway is a network connecting device/appliance that can be used to connect two devices in two different networks implementing different networking protocols and overall network architectures. The Internet Gateway Device (IGD) Standardized Device Control Protocol is a protocol for mapping ports in network address translation (NAT) setups, supported by some NAT-enabled routers. The protocol is standardized by the UPnP forum, and allows UPnP aware hosts to configure the device to allow incoming connections to the host.
HTTP/1.1 200 OK
CACHE-CONTROL: max-age = seconds until advertisement expires
DATE: when response was generated
EXT:
LOCATION: URL for UPnP description for root device
SERVER: OS/version UPnP/1.1 product/version
ST: search target
USN: composite identifier for the advertisement BOOTID.UPNP.ORG: number increased each time device sends an initial announce or an update message
CONFIGID.UPNP.ORG: number used for caching description information
SEARCHPORT.UPNP.ORG: number identifies port on which device responds to unicast M-SEARCH
@doc """
message => XML-formatted message that can be sent to a UPnP device to request its external IP address.
The message belongs to the UPnP service "WANIPConnection", which is used to manage internet
connection settings on the device.
GetExternalIPAddress => operation defined by upnp
WANIPConnection service. => service provided by some Internet Gateway Devices (IGDs) that
allow a device on a home network to request the public IP address of the IGD. pat of upnp protocol
allows a device to request the public IP address of the IGD, which can be used to set up port
forwarding or to allow the device to be accessed from the Internet.
"""
def get_external_address(%Nat.Protocol{service_url: url}) do