In tro d u c tio n to A s te ris k Mark Turner - PowerPoint PPT Presentation

In tro d u c tio n to A s te ris k Mark Turner Siteseers Inc. www.siteseers.com 12 June 2004

G o a ls ● T o b eco m e fam iliar w ith A sterisk 's purpo se an d o rg an izatio n ● T o step th ro ug h co n fig urin g ph o n e service usin g A sterisk

G lo s s a ry ● trunk - a phone line from the Central Office ● station - an internal phone ● FXO - "Foreign eXchange Office." phone interface to public telephone network (PSTN) ● FXS - "Foreign eXchange Station." internal phone interface. "Drives a phone." ● SIP - Session Initialization Protocol ● IAX - Inter - Asterisk eXchange

G lo s s a ry ● dialplan - tells a phone system what to do with dialed digits ● softphone - a phone implemented in software (i.e., Xten's X- Lite) ● hardphone - a SIP-capable telephone (such as the Cisco 7940) ● terminal adapter - a device which converts a standard phone into a SIP phone ● context - a way of partitioning phone calls. Can be used for security and/or organizational purposes ● codec - COder/DECoder. Compresses or expands binary data

G lo s s a ry ● PSTN - Public Switched Telephone Network - the traditional way of getting dialtone ● POTS - Plain Old Telephone System ● Phone Switch - a computer which connects calls (the "operator"). Asterisk can be one. ● Rate Center - a geographic location used to determine distance- related tolls (quaint?)

G lo s s a ry ● TDM - Time Division Multiplexing. A way of compressing many calls onto one circuit (T1) ● ISDN - Integrated Services Digital Network ("It Still Doesn't Work."). A 2 channel TDM digital line once marketed as the next generation phone service. Achieved blazing speeds of 128Kbps! ● PBX - "Private Branch eXchange." A computer which connects calls (see "switch.") Asterisk is a PBX.

C o d e c s ● G.729 - high-quality, low footprint codec. $10 Asterisk implementation. ~8k bps ● G.711 - uncompressed channel. Uses ~64k bps ● GSM - GSM compression. Decent quality, lower footprint ~13.2k bps ● G.723.1 - proprietary. Unsupported in Asterisk other than passthrough. ~6k bps ● G.726 – variable bandwidth. Not widely used? ● ILBC – open source codec. 15.2k bps

A T e le p h o n y P rim e r ● S im ple tech n o lo g y ● O ver 1 0 0 years o ld ● S m arts in th e sw itch

N e w T w is ts ● M u ltip le x in g ● F ib e r/D ig ita l (g o o d b y e m ic ro w a v e & sa te llite ) ● V o IP

T y p e s o f V o IP ● H .323 – O riginal. H igh overhead. Com plex. B loatw are? ● M G C P – M edia G atew ay C ontrol Protocol. SIP com petitor m eant to supercede H .323. ● SIP – Session Initialization Protocol. H TTP for the phone. Extensible. N A T-unfriendly. ● IA X – Inter-A sterisk eX change – A sterisk's ow n. Even low er overhead than SIP. N A T-friendly.

S IP P ro v id e rs ● Free (no PSTN access): Free W orld D ialup (FW D ), Skype, M SN M essenger ● Com m ercial: Tim e-W arner, Packet8, V oicePulse, V onage, FeatureTel, IConnectH ere ● M any, m any others.

H o w T o C h o o s e A P ro v id e r ● Q uality (Y ou G et W hat Y ou Pay For) ● Y our calling patterns ● Supported Rate C enters ● Support for your hardw are ● Price

W h a t Is A s te ris k ? ● S o ftw are P h o n e sw itch (P B X ) ● M ark S pen cer/D ig ium ● Z aptel h ard w are

S u p p o rte d P h o n e s ● M ost any SIP phone (C isco 79xx) ● M ost any SIP A TA (Packet8's D TA -310, Sipura SPA -2000) ● Softphones (X -Lite, LIPZ4, K phone, W indow s M essenger)

A s te ris k A P Is ● C h an n el A P I ● C o d ec A P I ● F ile F o rm at A P I ● A pplicatio n A P I

F ile la y o u t ● /etc/asterisk ● /var/lib/asterisk ● /var/log/asterisk ● Binaries in /usr/bin & /usr/sbin

A s te ris k D ia lp la n ● exten sio n s.co n f ● fo rm at ● co n texts

A s te ris k v o ic e m a il ● vo icem ail.co n f ● file fo rm ats ● em ail feature

P ra c tic a l E x a m p le s ● vo icem ail.co n f ● file fo rm ats ● em ail feature

R e s o u rc e s ● irc.freenode.net #asterisk ● w w w .asterisk.org ● w w w .digium .com ● w w w .voip-info.org ● w w w .pulver.com /fw d ● w w w .voxilla.org ● connect.voicepulse.com ● A sterisk's M ailing List

Q u e s tio n a n d A n s w e r