The most visited page in my blog is CUCM SIP Trunk to ITSP connection. From time to time my readers and students ask me to explain what the difference between the Early Offer and Delayed Offer in the SIP signaling is. Let’s say your ITSP want you to use SIP signaling with Early Offer in…
Good morning! I wanted to write this post long ago, however I was extremely busy and did not get around to take the required screenshots. And when preparing for the next course, I had to upgrade the firmware on our lab phones. So it became possible to write about what needs to be done on…
Good morning! A couple of weeks ago, I was troubleshooting a problem with poor voice quality when calling from Cisco Jabber software clients. The customer’s VoIP network covered several offices in different cities, CUCM 8.6 and СUP 8.6 were used. In general, there were about 1,500 users in their enterprise telephone network, and more than…
Good evening, colleagues! Today I’d like to tell you about how to install and change the background images of Cisco IP phones. This process is very well described in the phone Administration Guides, but I would still like to make some generalization for the most commonly used phone models and show the process itself using…
Good afternoon, At the CIPT1 course I am currently teaching in Almaty, one of the participants asked me to help with a problem, related to the Cisco 7911 phone. The phone refused to accept new software (the TFTP server had SCCP 9.2.3 firmware, CUCME v7.0 was used as the TFTP server). There was a message…
Good day! 🙂 After another business trip to the branch, I can’t sleep in the morning 🙁 – a 3-hour time difference affects, and I decided not to waste time and write a new post. It will tell you how to register a third-party SIP phone on Call Manager Express (hereinafter referred to as CUCME…