ATech Machine LIBRA-02 M Technical Information PDF herunterladen (Seite 611)

good idea to set ACLs to ensure that only devices on your local network can use the

accounts for the phones. Here is an example of doing that in /etc/asterisk/sip.conf:

[phoneA] ; Use a better account name than this.

type = friend

; Start by denying everyone.

deny = 0.0.0.0/0.0.0.0

; Allow connections that originate from 192.168.X.X to attempt

; to authenticate against this account.

permit = 192.168.0.0/255.255.0.0

The permit and deny options are accepted almost everywhere that connections to IP

services are configured. Another useful place for ACLs is in /etc/asterisk/man-

ager.conf, to restrict AMI accounts to the single host that is supposed to be using the

manager interface.

Tip #11: Use ACLs when possible on all privileged accounts for network services.

Another way you can mitigate security risk is by configuring call limits. The recom-

mended method for implementing call limits is to use the GROUP() and GROUP_COUNT()

dialplan functions. Here is an example that limits the number of calls from each SIP

peer to no more than two at a time:

exten => _X.,1,Set(GROUP(users)=${CHANNEL(peername)})

; *** This line should have no line breaks

same => n,NoOp(There are ${GROUP_COUNT(${CHANNEL(peername)})}

calls for account ${CHANNEL(peername)}.)

same => n,GotoIf($[${GROUP_COUNT(${CHANNEL(peername)})} > 2]?denied:continue)

same => n(denied),NoOp(There are too many calls up already. Hang up.)

same => n,HangUp()

same => n(continue),NoOp(continue processing call as normal here ...)

Tip #12: Use call limits to ensure that if an account is compromised, it cannot be used

to make hundreds of phone calls at a time.

Resources

Sometimes there are security vulnerabilities that require modifications to the Asterisk

source code to resolve. When those issues are discovered, the Asterisk development

team puts out new releases that contain only fixes for the security issues, to allow for

quick and easy upgrades. When this occurs, the Asterisk development team also pub-

lishes a security advisory document that discusses the details of the vulnerability. We

recommend that you subscribe to the asterisk-announce http://lists.digium.com/mail

man/listinfo/asterisk-announce mailing list to make sure that you know about these

issues when they come up.

Resources | 575

1 2 ... 606 607 608 609 610 611 612 613 614 615 616 ... 733 734

Kommentare zu diesen Handbüchern

Keine Kommentare

Compucase 6C11BS-U3T Scheda Tecnica (2 pagine)

Marchio: Compucase | Categoria: Computer cases | Dimensione: 0.25 MB |

Inglese

Indice

6C11BS-U3T

1

Più prodotti e manuali per Custodie per computer Compucase

Modelli	Tipo di Documento
6T18BS-U3T	Scheda Tecnica Compucase Mikro ATX Tower, 2 pagine
6218BS-U3T	Scheda Tecnica Compucase Midi Tower, 2 pagine
6K29BS-U3T	Scheda Tecnica Compucase 6K29BS-U3T computer case, 2 pagine
62R3BS-U3T	Scheda Tecnica Compucase 62R3BS-U3T computer case, 2 pagine
6C29BS-U3T	Scheda Tecnica Compucase Midi Tower, 2 pagine
67M3GB-U23T	Scheda Tecnica Compucase COUGAR Solution AF-2, 3 pagine
6C60BS-U3T	Scheda Tecnica Compucase Midi Tower, 2 pagine
6T10BS-U3T	Scheda Tecnica Compucase 6T10BS-U3T computer case, 2 pagine
7106B-UG	Scheda Tecnica Compucase 7106B-UG computer case, 2 pagine
6T18BS	Scheda Tecnica Compucase 6T18, 2 pagine
6HM6B-U3TL	Scheda Tecnica Compucase COUGAR Challenger, 3 pagine
6K28BS	Scheda Tecnica Compucase 6K28, 2 pagine
7K09B-U	Scheda Tecnica Compucase 7K09, 2 pagine
6K29BS	Scheda Tecnica Compucase 6K29, 2 pagine
6A21BS	Scheda Tecnica Compucase 6A21, 2 pagine
6K11BS-U3T	Scheda Tecnica Compucase 6K11BS-U3T computer case, 2 pagine
7KJCBS-FB30U	Scheda Tecnica Compucase Desktop 300W PSU, 2 pagine
6C11BS-UT	Scheda Tecnica Compucase 6C11, 2 pagine
6218BS-UT	Scheda Tecnica Compucase 6218, 2 pagine
6C28BS-1E40UT	Scheda Tecnica Compucase 6C28, 2 pagine