The remote device behind the NAT (terminal / gateway) within the same session has changed the source IP / Port. If the duration of the UDP NAT sessions is configured correctly, i.e. greater than the registration period, each device will send a request before the NAT session expires which therefore will never change. Each device […]
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The recording period set on the device is less than 60 seconds. The cause and the solution are simple. An incorrect period has been set and must be reset with a value between 60 and 120 seconds. Note that some terminals express the recording period in seconds (most of them) and others in minutes (Grandstream […]
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The UI fails to establish the connection SSE (server-sent events) The UI uses a permanent connection with the http protocol to receive notifications about the status of calls, users and gateways. The port used varies for each company and is indicated in the company configuration as “http port”. Possible causes: The firewall / antivirus of […]
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The call_manager received a response to an INVITE after at least 4 retransmissions It is a mitigated version of the Unreachable Device case and could occur together with it, due to too short NAT sessions on the router. Normally each invite should receive a 100 Trying response within a few milliseconds of sending. If the […]
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In a call with a gateway, the gateway call received less than a third of the rtp packets sent. In peer to peer (p2p) calls between terminals and telephone gateways, the system cannot detect any anomalies on voice / video traffic, since this traffic remains confined to the local network. Conversely, calls to and from […]
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The UI registration has expired. Periodically, each UI sends an update request from the active registration on the server (login refresh) and the system checks that this request arrives on schedule. Possible causes: There was an interruption in the network connection, for the same reasons explained in the Terminal or gateway registration timeout paragraph. Reasonably, […]
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The pbx received a clear request (INVITE \ REGISTER) and sent only one 401 (authentication challenge) after which nothing more arrived from the remote device. Possible causes: Although quite rare, there are terminals that do not support authentication via username and password. These terminals, once they receive a negative response with a 401, do not […]
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The pbx receives a request in clear text N times (INVITE \ REGISTER) despite having sent the challenge to authenticate with the 401 N times to the sender As seen previously in case 3), when there are terminals and / or telephone gateways that register on UCloud, the system operates as a SIP server. The […]
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Description of the problem: no more REGISTER packets have arrived from the terminal and \ or from the gateway and the registration session has expired. Each physical device that uses the SIP protocol (IP phones and telephone gateways) periodically sends (every 60-120 seconds) registration packets (REGISTER) to the server, indicating the registration period in the […]
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TRACK OF A CALL To carry out a rigorous debugging of a call with problems, the mere description of the phenomenon in words is not sufficient: this must support the trace of the call, which instead provides in a precise and often unambiguous way what happened during the call. To export the trace of a […]
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