May 10, 2024
Physical networking – Addressing Disconnected Scenarios with AWS Snow Family
AWS Snowball Edge devices have several Ethernet interfaces you can use to connect them to your network. The interfaces can operate at 1 Gbit/s, 10 Gbit/s, 25 Gbit/s, 40 Gbit/s, or 100 Gbit/s:
Figure 4.10 – Physical network interfaces (PNIs) on AWS Snowball Edge
Interfaces
RJ45: The RJ45 ports on an AWS Snowball Edge device support Ethernet over copper twisted-pair cables at either 1 Gbit/s or 10 Gbit/s. The interface will negotiate one or the other depending on what type of switch port is on the other end. Note that a 10 Gbit/s operation requires, at minimum, a Cat6a cable, or you can expect to drop packets. Cat8 cables are recommended.
Small Form-factor Pluggable (SFP) iteration 28: These are empty slots into which you must insert a transceiver module of some type. You must supply the transceiver module as none ship with an AWS Snowball device of any type. The 28 at the end refers to the fact that they can take Ethernet SFPs that go as fast as 25Gbit/s. These slots are also backward compatible with older 10 Gbit/s or even 1 Gbit/s modules:
Figure 4.11 – 25 GbE fiber optic (left) and 25 GbE RJ45 copper SFPs (right)
With SFP modules, you must supply the correct cable type as well. In the case of the 25 GbE fiber optic SFPs shown in Figure 4.11, those would be 50-micron LC-LC OM3 (or better) multimode cables. LC stands for Lucent Connector. They are the smaller squarish connectors that have a receive and transmit strand. OM3 stands for Optical Multimode version 3. These cables typically have an aqua colored jacket, a core size of 50 micrometers. In the case of 25 GbE over copper, a Cat8 twisted pair is required (see Figure 4.12):
Figure 4.12 – Cat8 twisted-pair RJ45 cable
Alternatively, 25 GbE SFP28 Twinax cables can be used in these slots. A Twinax cable, also called a direct-attach copper (DAC) cable, has transceivers on both ends and the cable is molded together as one big unit (see Figure 4.13). The cable part inside Twinax is copper, but it isn’t twisted-pair. It is essentially two coaxial cables bundled together – hence the name Twinax(ial):
Figure 4.13 – 25 GbE SFP28 Twinax cable
QSFP variant 28 – Like the SFP28 slots, these are empty sockets that you must insert a transceiver into. As is the case with the SFP28 slots, you must supply the transceiver yourself. Whereas SFP28 slots have a single 25 Gbit/s lane, the Quad part of QSFP28 denotes that these have four lanes. They can, therefore, support up to 100 Gbit/s over this single interface. Connectivity options remain the same as with SFP28, but in practice, Twinax cables are almost always used with QSFP. Note that these slots support older 40 Gbit/s modules as well:
Figure 4.14 – 100 GbE QSFP28 Twinax cable
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