Tek-Tips is the largest IT community on the Internet today!

Members share and learn making Tek-Tips Forums the best source of peer-reviewed technical information on the Internet!

  • Congratulations Chris Miller on being selected by the Tek-Tips community for having the most helpful posts in the forums last week. Way to Go!

Pri/Sip/T1Analog Trunk To PBX

Status
Not open for further replies.

technical10

Technical User
Nov 3, 2015
3
TT
How are those trunks differ from each other and can I have more than one of these of the same or different type for remote branch calls and outside calls?
 
Oh boy how basic a question, I was tempted to use LMGTFY but out of deference to others here....

PRI stands for Primary rate interface, and basically refers to both T1 and E1 interfaces and can be used for 24 or 32 channels into your system depending on which you use. However you can often use PRI but buy less channels (offerings where I live are 10, 20 or 30 nb 2 are used for signaling). There is also BRI (Basic Rate Interface) which you haven't mentioned which offers 2 channels per circuit and relies on the same technology. These services are also referred to as ISDN (Integrated Services Digital Network) and are a "Legacy" protocol traditionally delivered over Copper but increasingly these days via other means with copper for the last few feet!

Sip (Session Initiation Protocol) is an IP based means of delivering the services and is (unfortunately IMHO) the way Telecommunications is moving. These services can be delivered by any means the internet is delivered and can be simply an internet connection to the PABX. Sip can use compression to pack more calls down the bandwidth that you have using different CODECS but there can be trade offs, for example one codec uses a "voice lookup table" to predict information and so need less bandwidth but using this, your music on hold turns to cr@p. Another Codec can compress so much that your staff sound like robots.

The above is very basic but should give you some idea.

Now you can mix services on the PABX but you need to look at your reasons if you are going to because you would then use LCR (Least Cost Routing) to let the system decide which to use for each call.

a quick footnote is that SIP is not always used for trunking, it can be used to tie systems together for Toll bypass over the internet or even VoIP extensions in small branch offices or home worker situations. Just remember there is no QOS over the open internet so voice quality can degrade.

I'll leave it to others here to expand on this or correct me.
 
Status
Not open for further replies.

Part and Inventory Search

Sponsor

Back
Top