Transcript
Cable “modem” Converts high frequency content into digital data
Cable internet
Use ethernet output, not USB output. Only one per incoming line.
OR
ADSL microfilter
ADSL “modem”
High pass = data Low pass = voice BT line
Can have one per socket for every phone/fax extension, or one at the point of entry into the building, then two sets of wiring – one for phone/fax extensions, one for a single ADSL data connection.
ADSL data
Converts high frequency content into digital data Use ethernet output, not USB output. Only one per incoming line.
Firewall
Web filter
Router.
Only passes traffic for specific TCP/IP ports (sockets) at this TCP/IP address.
Filters out certain web sites by name or content (if enabled).
Maps internal LAN TCP/IP addresses and ports (sockets) to the external TCP/IP address (NAT = Network Address Translation).
Ethernet Switch (or Repeater - sometimes referred to as a “Hub”).
DHCP server
Generally 10/100 (Ethernet / Fast Ethernet), sometimes Gigabit ethernet.
Hands out TCP/IP addresses to internal LAN devices
Voice/fax
Telephone(s) only No ADSL Phones and faxes up to a maximum of the permitted REN value.
Mapping Functions to Physical Devices:
These functions are sometimes built in to the firewall/router device, most commonly a 4 port switch is built in. Often a wireless ethernet access point is included, sometimes an ADSL modem is included instead, or in addition.
Usually unmanaged (can’t see what’s happening through software) and cheap. Managed is better and gives you more control, but puts the price up a little. Unmanaged is fine for most SOHO networks. Big corporate network switches can have 100s of ports and all sorts of management features – at a price!
Wireless Ethernet Access Point(s) TCP/IP address(es) set locally (static). Wireless connections are “transparent”. Antenna placement is crucial.
Computers (PCs etc.) TCP/IP addresses supplied by DHCP server (dynamic)
Ethernet connected printservers (built-in to printer or standalone separate devices) TCP/IP addresses set locally (static)
Wireless clients (laptops, handhelds etc.) TCP/IP addresses supplied by DHCP server (dynamic)
These functions are almost always part of the firewall/router device
Wireless connections are “transparent”
Title: SOHO (Small Office / Home Office) network functional diagram. Author: Colin Butcher, XDelta Limited. Date: 7th March 2005, Issue: 1
