Lowest-level electronic or optical transmission functions of a network
"PHY" redirects here. For other uses, see PHY (disambiguation).
OSI model by layer
7. Application layer
NNTP
SIP
SSI
DNS
FTP
Gopher
HTTP (HTTP/3)
NFS
NTP
SMPP
SSH
SMTP
SNMP
Telnet
DHCP
NETCONF
more....
6. Presentation layer
MIME
XDR
ASN.1
ASCII
TLS
PGP
5. Session layer
Named pipe
NetBIOS
SAP
PPTP
RTP
SOCKS
X.225[1]
4. Transport layer
TCP
UDP
SCTP
DCCP
QUIC
SPX
3. Network layer
IP
IPv4
IPv6
ICMP (ICMPv6)
IPsec
IGMP
IPX
IS-IS
AppleTalk
X.25
PLP
2. Data link layer
ATM
ARP
SDLC
HDLC
CSLIP
SLIP
GFP
PLIP
IEEE 802.2
LLC
MAC
L2TP
IEEE 802.3
Frame Relay
ITU-T G.hn DLL
PPP
X.25 LAPB
Q.922 LAPF
IEEE 802.11
1. Physical layer
RS-232
RS-449
ITU-T V-Series
I.430
I.431
PDH
SONET/SDH
PON
OTN
DSL
IEEE 802.3
IEEE 802.11
IEEE 802.15
IEEE 802.16
IEEE 1394
ITU-T G.hn PHY
USB
Bluetooth
v
t
e
In the seven-layer OSI model of computer networking, the physical layer or layer 1 is the first and lowest layer: the layer most closely associated with the physical connection between devices. The physical layer provides an electrical, mechanical, and procedural interface to the transmission medium. The shapes and properties of the electrical connectors, the frequencies to transmit on, the line code to use and similar low-level parameters, are specified by the physical layer.
At the electrical layer, the physical layer is commonly implemented by dedicated PHY chip or, in electronic design automation (EDA), by a design block. In mobile computing, the MIPI Alliance *-PHY family of interconnect protocols are widely used.
Historically, the OSI model is closely associated with internetworking, such as the Internet protocol suite and Ethernet, which were developed in the same era, along similar lines, though with somewhat different abstractions. Beyond internetworking, the OSI abstraction can be brought to bear on all forms of device interconnection in data communications and computational electronics.
^"X.225 : Information technology – Open Systems Interconnection – Connection-oriented Session protocol: Protocol specification". Archived from the original on 1 February 2021. Retrieved 10 March 2023.
In the seven-layer OSI model of computer networking, the physicallayer or layer 1 is the first and lowest layer: the layer most closely associated with...
The physical-layer specifications of the Ethernet family of computer network standards are published by the Institute of Electrical and Electronics Engineers...
communications between systems are split into seven different abstraction layers: Physical, Data Link, Network, Transport, Session, Presentation, and Application...
transfers data between nodes on a network segment across the physicallayer. The data link layer provides the functional and procedural means to transfer...
control abstraction of the physicallayer such that the complexities of physical link control are invisible to the LLC and upper layers of the network stack...
Ethernet Advanced PhysicalLayer (Ethernet-APL) describes a physicallayer for the Ethernet communication technology which is especially developed for...
networking, an Ethernet frame is a data link layer protocol data unit and uses the underlying Ethernet physicallayer transport mechanisms. In other words, a...
link layer, and ISO 11898-2 which covers the CAN physicallayer for high-speed CAN. ISO 11898-3 was released later and covers the CAN physicallayer for...
is structured into seven conceptual layers. The layers form a hierarchy of functionality starting with the physical hardware components to the user interfaces...
whether the link layer, or any aspect of the TCP/IP model, covers OSI layer 1 (physicallayer) issues, or whether TCP/IP assumes a hardware layer exists below...
Technical Overview Define the OSI seven-layer architecture model the physicallayer, data link layer and application layer Network in addition to the signal...
logical topologies may be identical. A network's physical topology is a particular concern of the physicallayer of the OSI model. Examples of network topologies...
start and stop bits. In asynchronous serial communication in the physical protocol layer, the data blocks are code words of a certain word length, for example...
In the seven-layer OSI model of computer networking, the network layer is layer 3. The network layer is responsible for packet forwarding including routing...
PCI Express is a layered protocol, consisting of a transaction layer, a data link layer, and a physicallayer. The Data Link Layer is subdivided to include...
can be strictly scheduled and highly deterministic. Due to the unique physicallayer, common network sniffers such as Wireshark cannot be used to sniff ControlNet...
reported to the network layer. The exchange of data link units (including flow control) is defined by this layer. The physicallayer describes details like...
An application layer is an abstraction layer that specifies the shared communication protocols and interface methods used by hosts in a communications...
Control and PhysicalLayer Specifications Amendment 3: Enhanced Flexible Channel Wavelet (FCW) physical and media access control layers for use on any...
In the seven-layer OSI model of computer networking, the presentation layer is layer 6 and serves as the data translator for the network. It is sometimes...
electronics. SpaceWire replaced old PECL differential drivers in the physicallayer of IEEE 1355 DS-DE by low-voltage differential signaling (LVDS). SpaceWire...
standards include several wiring and signaling variants of the OSI physicallayer. Systems communicating over Ethernet divide a stream of data into shorter...
International Organization for Standardization as ISO 14230. One underlying physicallayer used for KWP2000 is identical to ISO 9141, with bidirectional serial...
Global Information