Cisco CPAK 100GBASE alternative = CFP2 converter + 100G QSFP28 module

Time ago we wrote blog article about Cisco CPAK transceivers, about how special it is and that there is no alternative in 3rd party market for it , since then things have changed and there is ONE now!


In short: we can use Cisco coded CFP2 converter (CFP2-QSFP28-CONV)


100G QSFP28 module in it, 100G-QSFP28-10 (Cisco PN: QSFP-100G-LR4-S)
And WUALA we have a solution!


Please kindly check below details about how our engineers managed to make 10km connection between Cisco Nexus 93108TC-EX (N9K-C93108TC-EX) which support QSFP28 ports and Cisco ASR 9000 (with A9K-MPA-2X100GE line card) which only support CPAK or CFP2 for ER4 connections.


Here is scenario:


At first when we are talking about connecting network routers first thing first, is to check datasheets, which are provided by router manufacturer, for complying (supported) transceivers.


Cisco Nexus 93108TC-EX:

By checking Nexus router compatible 100G transceivers we discover that there is a transceiver, which complies our initial requirements. Specifically QSFP28 form factor QSFP-100G-LR4-S For 10km connection. EDGE Technologies portfolio contains QSFP28 form factor transceivers (100G-QSFP28-10 for 10km connection). This transceiver is capable to reach 10km cable distance by utilizing 1310nm wavelength.


Cisco ASR 9000:

Specifically A9K-MPA-2X100GE board as mainstream supports Cisco propriety CPAK form factor, but as well, it has support CFP2-100G-ER4 (40km scenario).

In our case we have done tests using EDGE Optical Solutions 100G-QSFP28-10 for 10km connection (Cisco PN: QSFP-100G-LR4-S) together with CFP2-QSFP28 (PN: CFP2-QSFP28-CONV) converter adapter.


When such connection between Cisco Nexus 93108TC-EX (N9K-C93108TC-EX) and Cisco ASR 9000 (with A9K-MPA-2X100GE line card) has been made everything worked perfect! We can see the testing results below where 10km link is working and transceivers at both sides are recognized as valid:

Cisco ASR 9000 (A9K-MPA-2X100GE line card) side:


show controllers Hu0/5/0/0 all
Tue Dec  5 14:46:28.381 EET
Operational data for interface HundredGigE0/5/0/0:

    Administrative state: enabled
    Operational state: Up
    LED state: Green On


    Media type: R fiber over 4 Lane optics (long reach)
        Vendor: EDGE
        Part number: 100G-QSFP28-10
        Serial number: 1711100002
        Wavelength: 0 nm

    Digital Optical Monitoring:
        Transceiver Temp: 29.000 C
        Transceiver Voltage: 3.264 V

        Alarms key: (H) Alarm high, (h) Warning high
                    (L) Alarm low, (l) Warning low
           Wavelength    Tx Power          Rx Power      Laser Bias
        Lane  (nm)    (dBm)    (mW)     (dBm)     (mW)      (mA)
        --   -----   ------   ------    ------   ------    ------
        00     n/a     1.6   1.4464     0.3   1.0728     34.318
        00     n/a     1.0   1.2537     0.4   1.1041     33.020
        00     n/a     1.9   1.5329     -0.9   0.8123     31.564
        00     n/a     1.8   1.4997     -0.1   0.9685     30.956

Cisco Nexus 93108TC-EX (N9K-C93108TC-EX) side:

    transceiver is present
    type is QSFP-100G-LR4
    name is EDGE
    part number is 100G-QSFP28-10
    revision is 01
    serial number is 1711100002
    nominal bitrate is 25500 MBit/sec per channel
    Link length supported for 9/125um fiber is 10 km
    cisco id is 17
    cisco extended id number is 204