5520 Series switches can stack with themselves and support data rates of 40Gbps on ports U1 and U2 using the Native-V160 stacking mode with QSFP+ cables. High-speed 200Gb stacking is available on 5520 Series starting with Switch Engine 31.6 while using Native-V200. The two QSFP ports on the 5520 Series each provide 50Gb in both directions, resulting in 4x50Gb, or 200Gb total.
The 5520 Series can also stack with 5320 Series, 5420 Series, and 5720 Series switches.
When stacking with 5320 Series and 5420 Series switches (beginning with Switch Engine 31.6), the 5520 Series supports data rates of 10Gbps utilizing the 5520-VIM-4X installed on the 5520 Series. Either the Native-V40 stacking mode (10G link running at HG) with SFP+ cables can be used, or the Native-V stacking mode with SFP+ cables and alternate stacking ports (10G link running at HG) can be used.
Alternate stacking ports are 35 and 36 for models 5520-24T, 5520-24W, 5520-24X, 5520-24T-ACDC-BASE, and 5520-24X-ACDC-BASE. Alternate stacking ports are 59 and 60 for models 5520-48T, 5520-48W, 5520-12MW-36W, 5520-48SE, 5520-48T-ACDC-BASE, and 5520-48SE-ACDC-BASE.
When stacking with 5420 Series switches (beginning with Switch Engine 31.5), the 5520 Series supports data rates of 20Gbps on ports U1 and U2 using the Native-V80 stacking mode with QSFP+ to SFP-DD cables.
When stacking with 5720 Series switches, the 5520 Series supports data rates of 50Gbps on ports U1 and U2 using the Native-V200 stacking mode with QSFP28 cables.
5520 Series switches cannot stack with 5320 Series Extended Temperature switches and the 5320-16P-2MXT-2X switch.
