Audio delay issue due to Codec Setting in Grandstream IP Phones GRP26XX

Audio delay in Grandstream IP Phone

Description In an IP phone system, audio delay can occur due to network latency, jitter, and packet loss. In addition, audio codecs and processing that are used in IP phone systems can also contribute to audio delay. To reduce audio delay in IP phones, network administrators can use Quality of Service (QoS) techniques to prioritize … Read more

Phones are stuck at ‘Recovery Incomplete’

Recovery Incomplete Grandstream IP Phones GXP1625

Description This article describes the steps to troubleshoot the Grandstream IP Phones that are stuck at ‘Recovery Incomplete’ or ‘Firmware Initialising’ upon boot up. This is commonly found in GXP16XX series IP Phones – GXP1610, GXP1620, GXP1625, GXP1628 and GXP1630. Cause The error is caused by power failure or disruption during a firmware upgrade or … Read more

Grandstream Android Phone GXV32XX is not responsive when receiving incoming calls

Grandstream GXV32XX is not responsive in answering calls

Description This article describes Grandstream Android Phone GXV32XX as being not responsive when receiving incoming calls. The users are unable to answer or pick up calls from the LCD call screen. This scenario is seen after UCM firmware upgrade. Workaround Please try one of these methods: a. Go to UCM63XX’s WEB UI > Extension > Media  > … Read more

How to Block Ghost Calls on Grandstream IP Phones

How to Block Ghost Calls on the Phones

Description Ghost calls will usually affect the phone level. You may find it annoying by getting authorized calls. You can increase the security on the affected phone by setting the following parameter to YES in Grandstream IP Phones – GXP16XX/17XX/21XX and HT8XX ATAs models. Validate Incoming Messages Check SIP User ID for Incoming INVITE Accept … Read more

How to use Security Certificates on IP Phones – Grandstream GXP16XX/17XX/21XX

CA SSL Grandstream IP Phones

Description Upgrading the product to the latest firmware version allows the expiration date of Grandstream authorized certificates to be adjusted automatically. Even with the certificate expired, the communication between the phones and clients might not be secure or fully encrypted but the device will still function as normal. Downloads

‘CPE Connection Failed’ Warning

Description This article describes the CPE Connection Failed warning and how to get rid of the message pop-up. CPE Connection failure means that the phone cannot connect to the TR-069 or provisioning server (for eg. GDMS). You may disable or uncheck the TR-069 option under the phone’s Web Ui > System Settings > TR-069 to … Read more

Attended Transfer Call Flow

Attended Transfer Grandstream GXP2135

Description This article describes the call flow of Attended Transfer initiated by Grandstream GXP2135. VoIP packets and the phone’s Syslog messages will be discussed in this article. Call Flow a. Ext. 1001 dials Ext. 1007 b. Ext. 1007 puts the call on hold with ext. 1001 by pressing the Attn Transfer button on the Call … Read more

How to configure Remote Phonebook in Grandstream GRP26XX

Remote Phonebook Grandstream IP Phones
Starting, GRP261X adds the feature of Remote Phonebook.You may use the phonebook example here for testing purposes.   Login to Directory > Remote Phonebook:a. Phonebook Download Interval: set to 5 b. Remote Phonebook 1: name any c. HTTP/HTTPS Username : leave empty d. HTTP/HTTPS Password : leave empty e. Phonebook XML Server Path : f. Save and Applyg. Go ... Read more