Name vs extension number in queue_log

Hi

I have the following in the queue_log

1403701155|1403701154.152482|553|Local/41@from-queue/n|ADDMEMBER|
1403701155|1403701154.152482|591|Local/41@from-queue/n|ADDMEMBER|
1403701155|1403701154.152482|531|Local/41@from-queue/n|ADDMEMBER|
1403701203|1403701203.152485|70|NONE|ENTERQUEUE||02867298|1
1403701207|1403701203.152485|70|Susanne |CONNECT|4|1403701203.152494|3
1403701245|1403701134.152468|155|NONE|ENTERQUEUE||07362921735|1
1403701245|1403701134.152468|155|Local/5504@from-queue/n|RINGNOANSWER|0
1403701245|1403701134.152468|155|Local/5506@from-queue/n|RINGNOANSWER|0
1403701245|1403701134.152468|155|Local/5501@from-queue/n|RINGNOANSWER|0

I don’t know why for some extension appears the name (for example) Susanne and for other extension appear the extension number…

I would like to see only names… How can I do it?

Best regards