The Realtek Remote Control Protocol (RRCP), developed by

Realtek Realtek Semiconductor Corp. () is a Taiwanese fabless semiconductor company situated in the Hsinchu Science Park, Hsinchu, Taiwan. Realtek was founded in October 1987 and subsequently listed on the Taiwan Stock Exchange in 1998. Realtek has manu ...

, is an

application layer An application layer is an abstraction layer that specifies the shared communication protocols and interface methods used by hosts in a communications network. An ''application layer'' abstraction is specified in both the Internet Protocol Su ...

protocol, running directly over

Ethernet Ethernet ( ) is a family of wired computer networking technologies commonly used in local area networks (LAN), metropolitan area networks (MAN) and wide area networks (WAN). It was commercially introduced in 1980 and first standardized in 198 ...

frames. The main idea behind this protocol is to allow direct access to the internal register of an Ethernet switch controller (ASIC) over an Ethernet network itself. This approach allows to avoid cost of including a processor, RAM, flash memory, etc. in a managed Ethernet switch. Instead, all "intelligence" is targeted to reside in a nearby computer, running special RRCP-aware Ethernet switch management software. All RRCP packets are transmitted as

Ethernet frame In computer networking, an Ethernet frame is a data link layer protocol data unit and uses the underlying Ethernet physical layer transport mechanisms. In other words, a data unit on an Ethernet link transports an Ethernet frame as its paylo ...

s with

EtherType EtherType is a two- octet field in an Ethernet frame. It is used to indicate which protocol is encapsulated in the payload of the frame and is used at the receiving end by the data link layer to determine how the payload is processed. The same ...

0x8899. Details on the RRCP protocol are listed in the datasheets of some Realtek ASICs with RRCP support, including RTL8324BP and RTL8326. RRCP packet types are the following: * ''Hello'' – used to initiate a scan for RRCP-capable switches in a network segment, and to fetch some of their parameters. * ''Hello reply'' – sent by an RRCP-capable switch as a response to a valid "Hello" packet. Contains some their parameters, such as IDs, and MAC addresses. * ''Get'' – used to fetch the value from an internal register of the switch controller. * ''Get reply'' – sent by an RRCP-capable switch as a response to a valid ''Get'' packet. Contains requested register number and value, that was read from it. * ''Set'' – used to set an internal switch controller's register to a certain value. Contains register number and a value to be written to register. No acknowledgment is generated by a switch. * ''Loop Detect packet'' – not a part of RRCP protocol itself, but is closely associated, being an underlying mechanism for a simplified

Spanning Tree Protocol The Spanning Tree Protocol (STP) is a network protocol that builds a loop-free logical topology for Ethernet networks. The basic function of STP is to prevent bridge loops and the broadcast radiation that results from them. Spanning tree al ...

substitute in RRCP-capable switch controllers. * ''Echo request'' – not a part of RRCP protocol itself, but is closely associated, being an underlying mechanism for a Layer-2 analog of ICMP Echo request (Type 8) message in RRCP-capable switch controllers. * ''Echo reply'' – not a part of RRCP protocol itself, but is closely associated, being an underlying mechanism for a Layer-2 analog of ICMP Echo reply (Type 0) message in RRCP-capable switch controllers. Currently, RRCP protocol is officially working on Realtek's RTL8316BP, RTL8318P and RTL8324P switch controller chips. Unofficially, it also found to be working on RTL8316B, RTL8324, RTL8326 and RTL8326S. There are two software suites that are able to communicate with RRCP-capable switches. First is Realtek's own WinSmart utility and Vendor-derived variants from it. Second is the OpenRRCP open-source project. Additionally,

tcpdump tcpdump is a data-network packet analyzer computer program that runs under a command line interface. It allows the user to display TCP/IP and other packets being transmitted or received over a network to which the computer is attached. Distr ...

has an interpreter for RRCP packets.

References

{{Reflist

External links

OpenRRCP project
Internet protocols Application layer protocols