or pocket computer having a headset or speaker and microphone where the computer is connected by wires or wirelessly to the internet they may be stand alone internet ready telephones such as cisco 39 s 7902g ip phone connected either by an ethernet cable or by a wi fi ieee 802 11b c or g or wimax ieee 802 16a wireless connection to a lan that connects to the internet some may also be conventional telephones connected to the internet by means of some form of adapter for example a lan router having several conventional telephone ports such as the linksys model wrt54gp2 the illustrated sip telephones a 102 and b 106 may be any of these or they may take other conventional forms since internet telephones and the numerous ways in which they may be interconnected to the internet by wired and wireless lans and by other means are well known the details of such telephones and interconnections are not shown in accordance with the sip rfc internet telephone calls are established by the sip telephone a 102 entering into what is called a u201c sip transaction u201d with one or more proxy servers 108 and another sip telephone 106 a u201c sip transaction u201d begins with a sip request that may be forwarded or relayed ahead by one or.