On Aug 7, 2011, at 2:03 PM, Martin T wrote: > Lane, > while browsing the specifications of the optical modules listed in > this "Optical Interface Support—EX 3200 and EX 4200 Switches.pdf" > file: > > http://www.juniper.net/techpubs/en_US/release-independent/junos/topics/reference/specifications/optical-interface-support-ex-series.pdf > > ..all the modules have minimum and maximum launch power which differ > from each other quite a lot. What does this mean? Shouldn't the launch > power be consistent? In addition, what is a "Maximum Receiver > Sensitivity"?
you're looking at emitters with rather different properties... a 1000sx or 100fx multimode gbic is an 850nm emitter (that's visible wavelength red) and probably uses an led and is meant for 50 or 62.5micron multimode, a 850nm or 1310/1550 nm qsfp+ gbic uses a vertical cavity emitting laser. Maximum reciever sensitivity I think would normally be characterized as dynamic range. acceptable input power on the rx side would be between -1 and -25dBm on 1000baselr if it's higher than that, you may need to attenuate it.. for example if you put the 10Gb's ER gbics back-to-back you'll need an attenuator, to keep them from blinding each other. > David, Keegan, > thank you for explanation! > > > In addition, there isn't some sort of connection between Rx power and > Tx power, is there? I mean for example in case the received signal is > low, the transmit signal of the SFP/XFP is increased automatically? remember that the TX and RX are on different fibers which (you hope) have similar properties. > As > far as I know and as Lane confirmed, the Tx signal should be always > consistent.. > > > regards, > martin > > > 2011/8/3 Keegan Holley <keegan.hol...@sungard.com>: >> 2011/8/2 Joel Jaeggli <joe...@bogus.com> >> >>> >>> if these are sr multimode optics, the -15 number is low the -7 number is >>> marginal and everything else is decent. >>> >>> either the -15 one is quite long ( for sr) or needs to be >>> replugged/cleaned/reterminated >>> >>> >> Yea I agree. The -15 is a bit low unless it's is at the end of a really >> long, low-quality fiber run I'd clean it and or replace the XFP. It's >> blasting out at +1 and receiving much less, there could also be a mismatch >> of some sort. There are lots of ways to mismatch optics and cabling and >> still get link. >> >> >> >>> On Aug 2, 2011, at 2:53 PM, chip wrote: >>> >>>> Depending on whose optics you're using there should be a data sheet >>>> that shows the acceptable Tx/Rx levels for each type available from >>>> your vendor. I can't seem to locate a document for Juniper at the >>>> moment. But I assume they shouldn't be that far off from Cisco stuff. >>>> For example, here's a data sheet for the XENPAK module: >>>> >>>> >>> http://www.cisco.com/en/US/prod/collateral/modules/ps2797/ps5138/product_data_sheet09186a008007cd00_ps5455_Products_Data_Sheet.html >>>> >>>> Check Table-2. >>>> >>>> As far as I know, an optic will output power within a specified range >>>> as according to what type it is, SR, LR, ER, ZR, etc... >>>> >>>> Hope that helps a bit. >>>> >>>> >>>> On Tue, Aug 2, 2011 at 5:26 PM, Martin T <m4rtn...@gmail.com> wrote: >>>>> What is the acceptable Rx power in case of SFP/XFP? For example, here >>>>> are XFP Tx and Rx signals from six FXP's: >>>>> >>>>> 1: >>>>> Laser output power : 1.2920 mW / 1.11 dBm >>>>> Laser rx power : 0.0285 mW / -15.45 dBm >>>>> >>>>> 2: >>>>> Laser output power : 0.6420 mW / -1.92 dBm >>>>> Laser rx power : 0.3054 mW / -5.15 dBm >>>>> >>>>> 3: >>>>> Laser output power : 0.4230 mW / -3.74 dBm >>>>> Laser rx power : 0.5092 mW / -2.93 dBm >>>>> >>>>> 4: >>>>> Laser output power : 0.4180 mW / -3.79 dBm >>>>> Laser rx power : 0.4208 mW / -3.76 dBm >>>>> >>>>> 5: >>>>> Laser output power : 1.0920 mW / 0.38 dBm >>>>> Laser rx power : 0.1801 mW / -7.44 dBm >>>>> >>>>> 6: >>>>> Laser output power : 0.7680 mW / -1.15 dBm >>>>> Laser rx power : 0.3337 mW / -4.77 dBm >>>>> >>>>> >>>>> Is there some sort of pattern? It looks like if the Rx signal is >>>>> lower, the Tx is higher? And what can one consider a decent Rx laser >>>>> power level? >>>>> >>>>> >>>>> regards, >>>>> martin >>>>> _______________________________________________ >>>>> juniper-nsp mailing list juniper-nsp@puck.nether.net >>>>> https://puck.nether.net/mailman/listinfo/juniper-nsp >>>>> >>>> >>>> >>>> >>>> -- >>>> Just my $.02, your mileage may vary, batteries not included, etc.... >>>> >>>> _______________________________________________ >>>> juniper-nsp mailing list juniper-nsp@puck.nether.net >>>> https://puck.nether.net/mailman/listinfo/juniper-nsp >>>> >>> >>> >>> _______________________________________________ >>> juniper-nsp mailing list juniper-nsp@puck.nether.net >>> https://puck.nether.net/mailman/listinfo/juniper-nsp >>> >>> >> _______________________________________________ >> juniper-nsp mailing list juniper-nsp@puck.nether.net >> https://puck.nether.net/mailman/listinfo/juniper-nsp >> > > _______________________________________________ > juniper-nsp mailing list juniper-nsp@puck.nether.net > https://puck.nether.net/mailman/listinfo/juniper-nsp > _______________________________________________ juniper-nsp mailing list juniper-nsp@puck.nether.net https://puck.nether.net/mailman/listinfo/juniper-nsp