Month: August 2019

Introduction In this post we will learn how to upload SIP firmware to Cisco 7911 IP Phone. This will make possible using the phone with third party SIP servers. The instruction below applies to all Cisco 7900 series IP phones. Step 1. Download the SIP firmware. Before we start, let’s download the required SIP firmware

Introduction This article show step by step how to upgrade the firmware of a Cisco IP phone managed by CME(Call Manager Express). I will be upgrading Cisco 8851 IP phone(from version 12-0-1-11 to 12-5-1SR3-74) using Cisco ISR4331/K9 router as a CME. Step 1. Download the firmware files The first thing we need to do is