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  • 1.  LH/ZX 1G-SFP Not UP/UP - LAYER 1 Problem - or is it?

    Posted 01-15-2009 11:43

    Hi,

     

    I have 3 x MX240 connected in a triangle over CWDM equipment at distances of up to 30KM (1550nm, PROLABS SFP). There are 2 legs with one slightly longer than the other by a few KM. Two MX240 are at the same location connected by Multimode 10G XFP to complete the base of the triangle. Both legs go via different paths but terminate on the same MX240. All devices are running the same code.

     

    The slightly shorter leg is UP/UP and working. However, the longer leg is not. Both show approximately the same information

    from show commands.

     

    CWDM equipment already trunks/multiplexes production colours/wavelengths without fault. I have just connected my new gear to it on a different wavelength.

     

    One leg is working but the other is not. SFPS's are from the same manufacturer as is the CWDM equipment. The SFP's that aren't working have been swapped out with the ones that are and work OK (ish). Ports have also been changed. More of that later. Fibre has been cleaned and then replaced for brand-new. No difference.

     

    However, both links are displaying very similar show output with no alarming.

     

    There are two issues here.

     

    Working leg and non-working leg

     

    Neither work as plug and play. I have to reload or restart the DPC at a minimum (or reload) in order to bring the working leg online. But when it's online, it's stable.

     

    Non-working leg

     

    Although the show outputs are VERY similar, this refuses to come UP/UP.

     

    Some show output for the non-working leg:

     

    NB: Config is identical for working/non-working legs and output for the LASERS is virtually IDENTICAL. Configs have been modified ad-infinitum with no luck.

     

    Any ideas of how to troubleshoot this further?

     

    Best,

     

    Chris

     

     

    sh chassis pic pic-slot 0 fpc-slot 2    

     

    FPC slot 2, PIC slot 0 information:
      Type                             10x 1GE(LAN)
      State                            Online    
      PIC version                  0.0
      Uptime                         24 minutes, 13 seconds

    PIC port information:
                              Fiber                    Xcvr vendor
      Port  Cable type        type  Xcvr vendor        part number       Wavelength
      0     GIGE 1000LH       SM    PROLABS            ZX-SFP-1GIG-E     1550 nm

    show configuration interfaces ge-2/0/0 | display set    

     

    set interfaces ge-2/0/0 description

    set interfaces ge-2/0/0 speed 1g
    set interfaces ge-2/0/0 mtu 1552
    set interfaces ge-2/0/0 link-mode full-duplex

    set interfaces ge-2/0/0 no-gratuitous-arp-reply

    set interfaces ge-2/0/0 no-gratuitous-arp-request

    set interfaces ge-2/0/0 gigether-options auto-negotiation

    set interfaces ge-2/0/0 unit 0 family inet mtu 1500

    set interfaces ge-2/0/0 unit 0 family inet address x.x.x.x/30

    set interfaces ge-2/0/0 unit 0 family mpls


    show interfaces diagnostics optics ge-2/0/0             

     

    Physical interface: ge-2/0/0
        Laser bias current                        :  29.366 mA
        Laser output power                        :  1.4420 mW / 1.59 dBm
        Module temperature                        :  51 degrees C / 123 degrees F
        Module voltage                            :  3.2880 V
        Receiver signal average optical power     :  0.0104 mW / -19.83 dBm
        Laser bias current high alarm             :  Off
        Laser bias current low alarm              :  Off
        Laser bias current high warning           :  Off
        Laser bias current low warning            :  Off
        Laser output power high alarm             :  Off
        Laser output power low alarm              :  Off
        Laser output power high warning           :  Off
        Laser output power low warning            :  Off
        Module temperature high alarm             :  Off
        Module temperature low alarm              :  Off
        Module temperature high warning           :  Off
        Module temperature low warning            :  Off
        Module voltage high alarm                 :  Off
        Module voltage low alarm                  :  Off
        Module voltage high warning               :  Off
        Module voltage low warning                :  Off
        Laser rx power high alarm                 :  Off
        Laser rx power low alarm                  :  Off
        Laser rx power high warning               :  Off
        Laser rx power low warning                :  Off
        Laser bias current high alarm threshold   :  80.000 mA
        Laser bias current low alarm threshold    :  2.000 mA
        Laser bias current high warning threshold :  70.000 mA
        Laser bias current low warning threshold  :  4.000 mA
        Laser output power high alarm threshold   :  3.9810 mW / 6.00 dBm
        Laser output power low alarm threshold    :  0.5010 mW / -3.00 dBm
        Laser output power high warning threshold :  3.1620 mW / 5.00 dBm
        Laser output power low warning threshold  :  0.6310 mW / -2.00 dBm
        Module temperature high alarm threshold   :  125 degrees C / 257 degrees F
        Module temperature low alarm threshold    :  -40 degrees C / -40 degrees F
        Module temperature high warning threshold :  115 degrees C / 239 degrees F
        Module temperature low warning threshold  :  -40 degrees C / -40 degrees F
        Module voltage high alarm threshold       :  3.900 V
        Module voltage low alarm threshold        :  2.700 V
        Module voltage high warning threshold     :  3.700 V
        Module voltage low warning threshold      :  2.900 V
        Laser rx power high alarm threshold       :  3.9811 mW / 6.00 dBm
        Laser rx power low alarm threshold        :  0.0025 mW / -26.02 dBm
        Laser rx power high warning threshold     :  3.1623 mW / 5.00 dBm
        Laser rx power low warning threshold      :  0.0032 mW / -24.95 dBm
                        
    show interfaces ge-2/0/0 media 

     

    Physical interface: ge-2/0/0, Enabled, Physical link is Down
      Interface index: 139, SNMP ifIndex: 27
      Description: to

      Link-level type: Ethernet, MTU: 1552, Speed: 1000mbps,
      MAC-REWRITE Error: None, Loopback: Disabled, Source filtering: Disabled,
      Flow control: Enabled, Auto-negotiation: Enabled, Remote fault: Online
      Device flags   : Present Running Down
      Interface flags: Hardware-Down SNMP-Traps Internal: 0x4000
      CoS queues     : 8 supported, 8 maximum usable queues
      Current address: 00:21:59:0c:c5:2a, Hardware address: 00:21:59:0c:c5:2a
      Last flapped   : 2009-01-15 15:11:23 UTC (00:20:55 ago)
      Input rate     : 0 bps (0 pps)
      Output rate    : 0 bps (0 pps)
      Active alarms  : LINK
      Active defects : LINK
      MAC statistics:
        Input bytes: 0, Input packets: 0, Output bytes: 0, Output packets: 0
      Filter statistics:
        Filtered packets: 0, Padded packets: 0, Output packet errors: 0
      Autonegotiation information:
        Negotiation status: Incomplete

    sh chassis fpc pic-status 2  

     

    Slot 2   Online       DPCE 40x 1GE R
      PIC 0  Online       10x 1GE(LAN)
      PIC 1  Online       10x 1GE(LAN)
      PIC 2  Online       10x 1GE(LAN)
      PIC 3  Online       10x 1GE(LAN)

    sh chassis fpc 2    
                         Temp  CPU Utilization (%)   Memory    Utilization (%)
    Slot State            (C)  Total  Interrupt      DRAM (MB) Heap     Buffer
      2  Online            27      6          0       1024       18         30

    sh chassis fpc 2 detail  

     

    Slot 2 information:
      State                                 Online    
      Temperature                        27 degrees C / 80 degrees F
      Total CPU DRAM                   1024 MB
      Total RLDRAM                      256 MB
      Total DDR DRAM                   4096 MB
      Start time:                           2009-01-15 15:10:48 UTC
      Uptime:                               24 minutes, 18 seconds

     



  • 2.  RE: LH/ZX 1G-SFP Not UP/UP - LAYER 1 Problem - or is it?

     
    Posted 01-19-2009 09:56

    Hi Chris
     
    Seems your problem is an attenuation problem?
     
    Since Juniper's docs says for LH sfp in hardware guide :
     http://www.juniper.net/techpubs/en_US/release-independent/junos/information-products/topic-collections/hardware/mx-series/common/dpc-guide/frameset.html
    Average receive power:  –20 through –3 dBm
    Receiver sensitivity:  –20 dBm
     
    I can see in your outputs that you’re receiving at:
    Receiver signal average optical power     :  0.0104 mW / -19.83 dBm
    I can also see that the alarms should be raised at only
    Laser rx power low warning threshold      :  0.0032 mW / -24.95 dBm
     
    But the docs are saying that you're close to the limit
     
    I think you should compare precisely, on these parameters, your two links (the one working and the other that is not)
     
    HTH



  • 3.  RE: LH/ZX 1G-SFP Not UP/UP - LAYER 1 Problem - or is it?
    Best Answer

    Posted 01-23-2009 01:42

    Hi,

     

    After further analysis, it seems that the use of non-CWDM SFP's/XFP's which are manufactured to a lesser specification than CWDM approved kit will only work on CWDM equiopment if the wavelengths are matched by a spectrometer prior to deployment. In this way, it is possible to use non-CWDM transceivers on CWDM OP's. My supplier suggests that he is able to find /match cheaper transceivers that will work in this way in only 1/3 cases. So, the fact that RX power on both ends is too low for synchronisation is because the lambda of each transceiver at 1550nm is not close enough for the CWDM OP "grid".

     

    The solution to this problem therefore is to either:

     

    Match wavelengths of non-CWDM transceivers using a spectrometer that will work with CWDM OP's, OR

     

    Buy CWDM approved transceivers (>>expensive).

     

    Cheers