2022 9:44:49 AM Nova Southeastern University IP Address: 137.52.76.29 SDN Controller SWITCHES IN SDN There are two types of switch models were available in SDN, they are: Hardware based switch models software based switch models Hardware Based Switch Models of SDN OpenFlow reference standard is the main and early SDN enabling technologies being currently implemented in the commodity-networking hardware. Table 2 lists commercial switches that are at present available, along with their producer, and the version of OpenFlow they have implemented. This hardware functionality permits the device together match packets and then takes actions at a extremely high rate. However, it also presents a sequence of challenges to the SDN device developer. Specifically: How best to decode from flow entries to hardware entries; for example, how most excellent to use the CAMs, TCAMs, or hardware-based hash tables? Which of the flow entries to switch in hardware versus how many to drop back to using software? Table 2. Hardware implementations Manufacturer Switch Models OpenFlow Version Brocade NetIron CES 2000 Series, CER 2000 Hewlett packard 3500/3500yI,5400zI,6200zI,6600,8200zI Rackswitch G8264, G8264T Juniper EX9200 Programmable switch PF5240,PF5820 Pica8 P-3290,P-3295 Pronto 3290 and 3780 Broadcom BCM56846 Extreme networks BlackDiamond 8K, Summit Netgear GSM7352Sv2 Arista 7150,7500,7050 series Downloaded: 4/15/2022 9:44:49 AM Nova Southeastern University IP Address: 137.52.76.29 SDN Controller Most implementations are able to use hardware to handle some of the lookups, but others are handed off to software to be handled there. Clearly, hardware will handle the flow lookups much faster than software, but hardware tables have limits on the number of flow entries they can hold at any time, and software tables could be used to handle the overflow. How to deal with hardware action limitations that may impact whether to put into practice the flow in hardware versus software? For example, certain actions such as packet alteration may be