Why do Huawei OLT uplink ports usually work with optical modules of routers?

1. Huawei OLT uplink ports are standard Ethernet SFP/SFP+ interfaces.
2. Huawei’s system is generally open and flexible: as long as the transceiver is IEEE-compliant (e.g., 10GBASE-LR, SR, CWDM), it is usually recognized and works.
3. Huawei routers and switches also use standard optical modules, so the same module (e.g., 10GBASE-LR SFP+) can be inserted into both the OLT uplink port and the router port.

Why can’t Nokia OLT uplink ports?

Even though Nokia OLTs (e.g., ISAM series like 7360 FX-4/FX-8) have standard SFP/SFP+ physical ports, there are vendor-specific software controls that block ‘unapproved’ modules.

1. OLT is an access device:

Nokia OLTs (e.g., ISAM FX-4 / FX-8) are purpose-built for PON access networks. While they use standard SFP+ ports for uplink, they require officially certified transceivers.

For example, Nokia OLT FX-4 uplink port with a certified 3FE62600DA module works normally.

But when a technically identical 10G LR SFP+ module from another vendor (or even a Nokia module supplied for router use, PN starts with 3HE), its internal chipsets/firmware may differ, causing OLTs to reject it, status showing not-equipped or unsupported.

2. Different software stacks:

OLTs run access network firmware, whereas routers use SR OS. These different software platforms maintain separate compatibility lists and validation mechanisms. Some newer firmware versions also check for a digital signature in the transceiver.

3. Stricter module certification:

Nokia OLT software checks the transceiver’s EEPROM:

4. Direction matters:

Nokia enforces the whitelist only on the OLT uplink port. The router(e.g., the SR series) or switch on the other side is usually more flexible. As long as the transceiver meets IEEE standards, it usually works without needing special certification.

This creates an asymmetric situation:

Router ↔ Nokia OLT: the router side can use standard modules, but the Nokia OLT side must use an approved transceiver.

In summary:

1. Nokia OLT uplink ports perform stricter software-level checks and require vendor-certified optical modules. Otherwise, the port will not come up.
2. Nokia routers and switches are less restrictive: standard optical modules can often be used.
3. Even if both transceivers come from Nokia, the one without the access network certification (and signature) can’t be used in the OLT.

If you’d like to learn more or check detailed compatibility, feel free to contact us at sales@thunder-link.com.