support wiki

helpful humans at 423-456-6700

User Tools

Site Tools


System Setup
Getting Started
Setup Wizard
Porting Numbers
Caller ID
Special Projects

Network Introduction
Recommended Equipment
Ideal Network Setup
Firewall/Network Configuration
  Routers That Should Not Be Used
Ubiquiti ER X Configs
How To Disable SIP ALG
Networking Disasters
OpenVPN on Grandstream Phones
Port Forwarding / External Remote Phones

Customer Admin Portal
  Basic Mode
  Hold Music
  Advanced Mode
  PA Ring Tone
My Services
  International Calling
  Call Recordings
My Account
  Account Info

Functions & Advanced Features
Schedule Override
External Storage: USB
Hold vs Park
Hunt Groups
Line Emulation
Relay/Door/Alarm Control
Feature Code List
Grandstream Wave

Hello Hub V2
Hello Hub Nano - Cloud Connector
Supported Phones (Auto-Config)
Grandstream HT801/802 Tricks
Pairing Instructions for DP750/752
Grandstream WP820
PA Speaker (SIP) Configuration

Hello Hub V1
Hello Hub V1 Battery Removal
Manual Config Phones

Switching Loops
Email Notes

Payment Policy

System Variants
System & Hardware Variants

Terms and Conditions
Software Licensing

Blog and Rants
Recording Phone Calls & Conversations



Clues of network issues

Sometimes it takes experienced eyes on the ground. This is a slightly edited copy of an email sent this morning (3/31/2021) after several hours of strange network behavior troubleshooting. I hope to update this soon.

The email

Ada, Sarah, James,

The really curious strange issue was not being able to dial out from 2 different phones at James's location and/or extension 101. We tried several things, including changing his extension number and moving that phone to a different location and ethernet cable.

I made it work by changing his “transport” from UDP (Unidirectional) which is the standard, to TCP. While it works, it's indicative of issues with your network / firewall configuration and or the use of range extenders or bad ethernet switches. Your network is not very large, but it may be more than the ethernet switch and Netgear firewall at that location can handle. It's time for a checkup visit from a decent business network technician and possibly some wiring checks.

My #2 indicator is the ping time to the phones at James's desk. More than 1ms for a physical ethernet cable to a good phone like his GXP2170 or GRP2614 is a sign of poor cabling or equipment. You may note that the ping times to the other phones at that location are all under 1ms.

If I/we can assist a network technician, we are more than willing and able. There is a level of skill and awareness of conditions that an experienced tech can do on site that we can not achieve from remote.

Summary of all of this: It's time for a checkup from a network/IT professional.

The image below is a display from the tool that scans the network, finds and configures phones and is available on your customer web portal at:

blog/clues_of_network_issues.txt · Last modified: 2022/06/10 16:55 by mike