Networking and DOS attacks

[john () johnmachell wanadoo co uk]

I am very new to networking. I have a Netgear ADSL modem/router with a firewall that is set to allow all outgoing 
traffic and block all incoming and to send me a security log each day. Please could someone to tell me what the log 
means (see below) and whether I should be concerned or not as, since the DOS and UDP messages started appearing I seem 
to get lots of disconnections from my ISP. Cheers, John

Thu, 1970-01-01 01:00:16 - Initialize LCP.
Thu, 1970-01-01 01:00:16 - LCP is allowed to come up.
Thu, 1970-01-01 01:00:20 - CHAP authentication success Thu, 1970-01-01 01:00:35 - Send out NTP request to 
time-g.netgear.com Tue, 2006-05-02 08:57:03 - Receive NTP Reply from time-g.netgear.com Tue, 2006-05-02 08:56:28 - 
Router start up Tue, 2006-05-02 09:22:01 - UDP Packet - Source:199.2.51.139,50244 Destination:81.79.70.215,1029 - [DOS] 
Tue, 2006-05-02 09:28:58 - UDP Packet - Source:222.208.168.130,49057 Destination:81.79.70.215,1033 - [DOS] Tue, 
2006-05-02 09:28:59 - UDP Packet - Source:150.64.232.13,30794 Destination:81.79.70.215,1026 - [DOS] Tue, 2006-05-02 
09:52:41 - UDP Packet - Source:61.156.42.117,38734 Destination:81.79.70.215,1032 - [DOS] Tue, 2006-05-02 09:52:41 - UDP 
Packet - Source:61.156.42.117,38734 Destination:81.79.70.215,1033 - [DOS] Tue, 2006-05-02 09:52:41 - UDP Packet - 
Source:61.156.42.117,38734 Destination:81.79.70.215,4081 - [DOS] Tue, 2006-05-02 09:52:41 - UDP Packet - 
Source:61.156.42.117,38734 Destination:81.79.70.215,2 - [DOS]

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