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Negative. The SF300 is 802.3af PoE standard only, the older 7940/60 phones are pre-standard and not compatible with 802.3af. You have to use power bricks, or get a Cisco switch that is backwards compatible as well as standard.<br />
We've run into this issue on several newer Cisco switches with old Cisco phones..
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Negative. The SF300 is 802.3af PoE standard only, the older 7940/60 phones are pre-standard and not compatible with 802.3af. You have to use power bricks, or get a Cisco switch that is backwards compatible as well as standard.
We've run into this issue on several newer Cisco switches with old Cisco phones..

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any idea what switches are bACKWard compatible?
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any idea what switches are bACKWard compatible?

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Have existing Cisco IP7940/7960 phones and would like to use them with new replacement Cisco Switches (SF300-24P) but the phones won't power up. &nbsp;They will power up on degrading Cisco Catalyst 3500 Series phones. &nbsp;Is there some way to get the new switches to power the phones?<br />
<br />
Jim
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Have existing Cisco IP7940/7960 phones and would like to use them with new replacement Cisco Switches (SF300-24P) but the phones won't power up.  They will power up on degrading Cisco Catalyst 3500 Series phones.  Is there some way to get the new switches to power the phones?

Jim

How do I get Cisco IP79450/7960 phones to use Poe on Cisco SF300-24P Poe Switches

Voice over IP (VoIP) is a methodology and group of technologies for the delivery of voice communications and multimedia sessions over Internet Protocol (IP) networks, such as the Internet. Other terms commonly associated with VoIP are IP telephony, Internet telephony, broadband telephony, and broadband phone service. The term specifically refers to the provisioning of communications services (voice, fax, SMS, voice-messaging) over the public Internet, rather than via the public switched telephone network (PSTN).  Examples of the VoIP protocols are H.323, Media Gateway Control Protocol (MGCP), Session Initiation Protocol (SIP), H.248 (also known as Media Gateway Control (Megaco)), Real-time Transport Protocol (RTP), Real-time Transport Control Protocol (RTCP), Secure Real-time Transport Protocol (SRTP), Session Description Protocol (SDP), and Inter-Asterisk eXchange (IAX).

Voice Over IP

A switch is a device that filters and forwards packets of data between LAN segments. Switches operate at the data link layer or the network layer of the Open Systems Interconnection (OSI) Reference Model and therefore support any packet protocol. LANs that use switches to join segments are called switched LANs or, in the case of Ethernet networks, switched Ethernet LANs. A hub is a connection point for devices in a network. Hubs are commonly used to connect segments of a LAN. A hub contains multiple ports; when a packet arrives at one port, it is copied to the other ports so that all segments of the LAN can see all packets.

Switches / Hubs

Networking hardware includes the physical devices facilitating the use of a computer network. Typically, networking hardware includes gateways, routers, network bridges, modems, wireless access points, networking cables, line drivers, switches, hubs, and repeaters. But it also includes hybrid network devices such as multilayer switches, protocol converters, bridge routers, proxy servers, firewalls, network address translators, multiplexers, network interface controllers, wireless network interface controllers, ISDN terminal adapters and other related hardware.