Number of telephone extentions This topic has 0 replies, 1 voice, and was last updated 7 years, 8 months ago by Mohamed Abbas. Viewing 1 post (of 1 total) Author Posts 18th May 2013 at 13:01 #69057 Reply Mohamed AbbasGuest Hi, We have around 1100 staff moving to a new building, my question is how many telephone extension should be considered? and how many spare of future expansion should be calculated? is there a formula used? Author Posts Viewing 1 post (of 1 total) Reply To: Number of telephone extentions Your information: Name (required): Mail (will not be published) (required): You may use these <abbr title="HyperText Markup Language">HTML</abbr> tags and attributes: <a href="" title="" rel="" target=""> <blockquote cite=""> <code> <pre class=""> <em> <strong> <del datetime="" cite=""> <ins datetime="" cite=""> <ul> <ol start=""> <li> <img src="" border="" alt="" height="" width=""> Submit