Form Factor

Juniper's 400G transceivers cater to the growing demand for bandwidth in metro, edge, core, and data center networks. To support the multivendor network environment, Juniper 400G transceivers adhere to key industry standards.

Form factor refers to the physical dimensions and shape of a transceiver. Form factor includes aspects like the size, shape, connector type, and other physical characteristics. It determines how the transceiver fits into networking equipment like switches, routers, or servers.

Juniper supports the QSFP-DD (Quad Small Form Factor Pluggable Double Density) form factor for 400G transceivers. QSFP-DD uses an 8x50G electrical interface to achieve a total bandwidth of 400Gbps. The QSFP-DD form-factor is defined by the QSFP-DD MSA industry consortium. Juniper is a founding member of the consortium. QSFP-DD can accommodate more ports per unit area than other form factors. Hence, QSFP-DD form factor is ideal for networks that require high-density port layouts such as a data center.

The QSFP-DD host cage design supports backward compatibility with QSFP28 and QSFP. You do not need any external mechanical adapter to support legacy transceivers. QSFP-DD is both forward and backward compatible.

Note:

Juniper does not currently support OSFP (Octal Small Form-Factor Pluggable) for 400G transceivers. However, OSFP transceivers used in third-party platforms can be interoperable with Juniper's QSFP-DD transceivers in a 400 Gbps network. If you are using third-party OSFP transceivers in your network, the IEEE standard (DR4, LR4, FR4 and so on) of the transceivers must be consistent.

Note:

The OSFP optical transceiver does not fit into a QSFP-DD port.

Quad Small Form Factor Pluggable Double Density (QSFP-DD)

QSFP-DD ports are smaller in size than ports with OSFP form factor. Hence, you can accommodate more ports per unit area. QSFP-DD form factor is ideal for networks that require high-density port layouts. QSFP-DD is compatible with QSFP56, QSFP28, and QSFP+ modules.

Table 1: Features of QSFP-DD Form Factor
Feature	QSFP-DD	Notes
Size	Small
Heat sink	Standard heat sink limited by size constraints. Supports a riding heat sink
Connector style	Small connector with 76 connector pins (16 differential pairs, the remaining pins being power, ground, status and control pins.)	The connectors are designed for high-density connections.
Power consumption	Gray optics: up to 14 W
Power consumption	ZR/ZR+ tunable DWDM optics: 18 W through 23 W
Thermal requirements	Standard: 0 through 70° C High power modules: 75° C to 80° C	Transceiver modules with QSFP-DD form factors are designed to operate within the case temperature ranges provided.
Backward compatibility	Compatible with some of the other QSFP transceiver module ports such as QSFP56, QSFP28, and QSFP+.	Backward compatibility with the existing hardware ensures smooth transition, upgrade, operational flexibility, and cost savings.