LAN PHY and WAN PHY are different protocols, you cannot intergonect it together. WAN PHY can be connect to POS STM 64 interface. Cisco will annononce this year WAN PHY Xenpak, it maybe will be solution for you.

As far I know, the LX4 has internal CWDM Mux/Demux which send 10G via 4 times 2,5 G. It is standard, but noone support it. You can connect just LX4 again another LX4 Xenpak, but not to another one. On the other hand the distnance is longer then SR LR...

Hi we have only WinXP in our company and CTC works fine. Someone has problem to run corect version of Java.

Hi,3845 does not support Gbic, but SFP. To buy SFP is cheaper thaen another 3750 switch. Question is about traffic, I am not sure that on GigE port, 3845 is wire speed

I hace used both technology (but never mixed together). As far as I know both has broadband recieer, so you can plug in DWDM GBIC to customer port of LT DWDM. Just only check the power, if it is short distance you will need attenuator maybe.Regards