Category Archives: Uncategorized

Yeastar S20 Voip Pbx – An Efficient VoIP PBX Solution for Small Businesses

Yeastar S20 Voip Pbx - An Efficient VoIP PBX Solution for Small Businesses

In today’s highly competitive business environment, effective communication is crucial for the success of any organization. Small businesses, in particular, need a reliable and cost-effective communication system to stay connected with customers, partners, and employees. The Yeastar S20, part of the S-Series VoIP PBX lineup, is a feature-rich solution designed to meet the unique requirements […]

Evaluating Yeastar P550 phone system

Yeastar P550 phone system

The Yeastar P550 VoIP IP PBX Phone System is a solution designed for small to medium-sized businesses. Here’s a summary of its specifications: The Yeastar P550 VoIP IP PBX Phone System provides essential features for call management, such as call routing, call forwarding, call waiting, and voicemail. It supports SIP (Session Initiation Protocol) and is […]

Streamline Your Business Communications with Yeastar S20 VoIP PBX

Yeastar Voip PBx Kenya

In today’s fast-paced business environment, effective communication is key to success. Traditional telephone systems are becoming outdated and expensive to maintain, leading many businesses to adopt Voice over Internet Protocol (VoIP) solutions. Yeastar S20 VoIP PBX is a powerful communication system designed to meet the needs of small and medium-sized enterprises. In this blog post, […]

Unable to Make Outbound or Inbound Calls through SIP Trunk – ACL Strategy on Provider Side

Applicability Firmware version: Any Model: S-Series Problem Description User was not able to make outbound or inbound calls through SIP trunk. Analysis In PCAP file for a test outgoing call, pbx has sent INVITE to SIP provider but it didn’t reply any message to PBX, in this case it’s better to check with the provider. […]

Unable to Receive Incoming Calls from the SIP trunk – Session Timer Required

Applicability Firmware version: Any Model: S-Series, U-Series Problem Description When receiving the incoming call through the SIP trunk, S-series PBX reply ‘421 Extension Required’, then the incoming call fails. Analysis The PCAP log shows S-Series PBX refused the call, then required ‘Timer’, which means S-series PBX requires the SIP provider sends ‘session timer’ at the […]

Incoming Call Failure – Caused by Default SIP Port 5060 on PBX Changed

Applicability Firmware version: Any Model: S-Series Problem DescriptionCreate one SIP peer trunk which applied from carrier, the trunk status shows up. But incoming call can not land to PBX, outgoing call from PBX to external number works fine. AnalysisAnalysis on the PCAP captured on PBX side.As the following figure indicated, PBX respond “Destination Unreachable” based […]

Internal Call Failure – SRTP is not Enabled on the Phone

Applicability Firmware version: Any Model: S-Series, U-Series Problem Description User failed to make the internal calls.  Analysis The PCAP log shows the RTP is encrypt in SDP that sent to the phone. It’s highly possible that the SRTP is not enabled on the phone when you registered the extension. Solution You can choose either solution: […]

Unable to Make Calls by TA FXS Ports – Invalid Caller ID Number Configured

Applicability Firmware version: Any Model: TA FXS Problem Description Client reported that he could not make calls from TA3200 FXS port. Receiving calls was working fine. TA3200 was provisioned by S100. Analysis SIP log on S100 shows error: PJSIP syntax error exception when parsing ‘ ‘ headers on line 4 col 36; The problem comes […]

One-way Audio after Hold Retrieve from Cisco CUCM Extension

Applicability Firmware version: Any Model: U-Series & Gateways Problem Description The problem could be like: The gateway is interconnected with Cisco CUCM by SIP trunk. The one-way audio issue happens when the call is retrieved from hold by CUCM extension. One-way audio after call established. In the case of One-way Audio after Hold Retrieve from […]

The Router Settings Relevant with One Way Audio & 30 Seconds Call Hang up Issue

Users might meet the SIP Call issue including: One way audio No audio in both way Call hangs up at 30 seconds Mostly it is relevant to the router, firewall, or VPN gateway settings. We often suggest client disable SIP ALG, SIP forwarding or something like that. Specifically the one-way audio or no audio issue. […]