Got my hands on a fully DWDM C-band tunable XFP today! Didn't take long before it was properly seated in a small MX80 I have in close vicinity. Soon later, disappointed and dismayed to see a peak pegged to 1550nm on my spectrum analyzer...
Putting the tunable optic in one of the four built-in 10GE ports only resulted in it transmitting on 1550nm - the default on JUNOS boxes. Setting or not setting wavelength (under optic-options on the interface configuration) didn't have any effect at all.
If I on the other hand used a 10GE port on a MIC, the XFP would adjust to whatever wavelength I set in the configuration.
Discussing the matter with lord Ytti soon led to the XFP once again being seated in a built-in port and I launched a shell on the internal CPU on the FEB.
kll@ROUTER> start shell pfe network tfeb0 TFEB platform (1000Mhz MPC 8544 processor, 1024MB memory, 512KB flash) TAZ-TBB-0( vty)# test xfp 5 alarm test xfp
alarm data-rate set xfp data rate laser set xfp laser loopback xfp loopback periodic xfp periodic power set XFP power presence check presence of xfp read xfp read register stats-clear clear xfp stats wavelength set xfp wavelength write xfp write register TAZ-TBB-0( vty)# test xfp 1 presence xfp-0/0/0 is present TAZ-TBB-0( vty)# test xfp 2 presence xfp-0/0/1 is present TAZ-TBB-0( vty)# test xfp 3 presence xfp-0/0/2 not present
0/0/1 looks like my horse and so let's try setting wavelength;
TAZ-TBB-0( vty)# test xfp 2 wavelength 1537 Error, command returned 7 error code TAZ-TBB-0( vty)#
TAZ-TBB-0( vty)# test xfp 2 wavelength 153700 TAZ-TBB-0( vty)#
... and the spec' says: 1537.025nm! So it seems that the hardware indeed is capable of setting the wavelength on the XFP - it's just JUNOS that doesn't properly pass the information from the configuration to the FEB.
Another rather interesting thing I noticed was that after a while, the XFP, when inserted in a built-in port, jumps to a different wavelength for no apparent reason. A minute later it jumps again and continues to do this. It does not appear to be temperature related, since it's very stable at 1550nm if I don't touch anything. Not sure if the FEB might be writing random bits to the XFP as it is in some form of "unknown state" after I manually set the wavelength.. remains to be seen once the wavelength tuning bug is fixed in JUNOS.
Turn on, tune in and tune out!
UPDATE: This should be supported in JUNOS 11.2 and later.. let's wait and see :)