Monthly Archives: maio 2015

Curiosidade na saída do df -h

Índice

  • Do not be alarmed about the size: importantly, many people running df -h and knowing that /run is backed by RAM are shocked that their precious memory is being “wasted” by these mysterious folders. Just like the Linux ate my RAM myth though, this belief is incorrect.
    • The size shown is only the maximum that may be used
    • It defaults to 50% of physical RAM
    • Only as much shown in the Used column is actually in use, which in the above screenshot is less than 1 megabyte total

Opensips Features

tux_matador

Bom esse é um assunto que um dia espero dar mais detalhes, não é algo comumente utilizado e ou falado, eu diria que é mais coisa de especialistas, mais para operadoras que estão migrando sua telefonia velha “legado” para o novo padrão mundial o SIP, o que posso adiantar é que o opensips é ambicioso, diz que pode manter até 5000CPS ou seja chamadas por segundo e pode ter 3milhões de usuários isso são números bem interessantes e milhares de vezes maiores que o asterisk que foi concebido para outra coisa, não entrarei nesta conversa. Para quem quer saber algumas caracteristicas do opensips abaixo alguns features sobre o mesmo.

Some of the features that OpenSIPS brings:

  • robust and performant SIP (RFC3261) Registrar server, Location server, Proxy server and Redirect server
  • small footprint – the binary file is small size, functionality can be stripped/added via modules
  • plug&play module interface – ability to add new extensions, without touching the core, therefore assuring a great stability of core components
  • stateless and transactional statefull SIP Proxy processing
  • support for UDP/TCP/TLS/SCTP transport layers
  • IPv4 and IPv6
  • support for SRV and NAPTR DNS
  • SRV DNS failover
  • IP Blacklists
  • multi-homed (mhomed) and multi-domain support
  • flexible and powerful scripting language for routing logic
  • variables support in script – script variables, pseudo-variables (access to the SIP messages), AVPs (values persistent per SIP transactions)
  • management interface via FIFO file and unix sockets
  • authentication, authorization and accounting (AAA) via database (MySQL, Postgress, text files), RADIUS and DIAMETER
  • digest and IP authentication
  • Presence Agent support (many additional integration features)
  • XCAP support for Presence Agent
  • CPL – Call Processing Language (RFC3880)
  • SNMP – interface to Simple Network Management Protocol
  • management interface (for external integration) via FIFO file, XMLRPC or Datagram (UDP or unixsockets)
  • NAT traversal support for SIP and RTP traffic
  • ENUM support
  • PERL Programming Interface – embed your extensions written in Perl
  • Java SIP Servlet Application Interface – write Java SIP Servlets to extent your VoIP services and integrate with web services
  • load balancing with failover
  • least cost routing
  • support for replication – REGISTER offer new functions for replicating client information (real source and received socket).
  • logging capabilities – can log custom messages including any header or pseudo-variable and parts of SIP message structure.
  • modular architecture – plug-and-play module interface to extend the server’s functionality
  • gateway to sms (AT based)
  • multiple database backends – MySQL, PostgreSQL, Oracle, Berkeley, flat files and other database types which have unixodbc drivers
  • straightforward interconnection with PSTN gateways
  • dialog support (call monitoring, call termination from proxy side, call profiling)
  • XMPP gateway-ing ( transparent server-to-server translation)
  • impressive extension repository – over 70 modules are included in OpenSIPS repository

Scalability:

  • OpenSIPS can run on embedded systems, with limited resources – the performances can be up to hundreds of call setups per second
  • used a load balancer in stateless mode, OpenSIPS can handle over 5000 call setups per second
  • on systems with 4GB memory, OpenSIPS can serve a population over 300 000 online subscribers
  • system can easily scale by adding more OpenSIPS servers
  • OpenSIPS can be used in geographic distributed VoIP platforms
  • straightforward failover and redundancy

How To: Originate Call From Asterisk CLI

tux_asterisk

This is a useful command when building your dial plan, it allows testing of the dial plan remotely. There are a couple of commands to explain. The first is the originate command a highly useful tool for checking any IVR context’s, this is how to use it.

originate SIP/14075551234@sip-outbound extension s@auto-att

Let me explain this.:

originate = command

SIP/14075551234 = what technology to use so this could be IAX.,SIP,ZAP,DHADI following a slash and phone number

@sip-outbound = this is what context to send it to in sip.conf or other associated technology file

extension = is required for the command

s = this is what exten to send to within the context specified below ( decorem)

@auto-att = which context to send to in extensions.conf

Now the other way to dial out from the system is with the dial command which is show below.

dial 14075551234@internal

dial = the command

14075551234 = the digits to send, so this could be anything you want it just has to match something in the context you specify

@internal = the context you would like to match the digits in extensions.conf

Bash no Freebsd ?

tux_bsd

Curiosidade… o bash não vem por padrão no freebsd vou postar uma informação mais detalhada direto do freebsd.org que fala sobre isso.

Shells: Sem Bash?

Usuários vindos do Linux® são frequentemente surpreendidos por não encontrarem o Bash como o shell padrão no FreeBSD. De fato, o Bash nem mesmo está presente na instalação padrão. Em vez disso, o FreeBSD usa o tcsh(1) como shell padrão. Embora o Bash e seus outros shells favoritos estejam disponíveis na Coleção de Ports do FreeBSD.

Se você instalar outros shells, o chsh(1) poderá ser usado para definir o shell padrão dos usuários. Contudo, é recomendável que o shell padrão do root permaneça inalterado. A razão para isso é que shells não incluídos na base do sistema são normalmente instalados em /usr/local/bin ou /usr/bin. Caso ocorra um problema no sistema de arquivos no qual estão localizados o /usr/local/bin e o /usr/bin, eles não poderão ser montados. Neste caso, o usuário root não teria acesso ao seu shell padrão, o que o impediria de efetuar login. Por este motivo uma segunda conta root, a conta toor, foi criada para uso com shells que não fazem parte da base do sistema. Leia o FAQ de segurança para obter informações sobre a conta toor.