All my remote extensions are showing port number 5090, except the extension
2013.
Why does it show port 56588 ?

Call-ID:  OTJlMGM3NWY4OTAyMDIwODEwODMwYjM5N2UyYjBiZGU.
User:     2013@henkoegema.ftpaccess.cc
Contact:  "Simon" <sip:2013@xx.205.1.28:56588;rinstance=defd850666661ca9>
Agent:    Zoiper for Windows rev.599
Status:   Registered(UDP)(unknown) EXP(2008-11-13 11:59:51)
Host:     freeswitch


Henk.