 activated D-channel. The network should respond with an IDENTITY ASSIGN message containing a TEI that will be used in all future messages between this particular terminal and the network. This automatic TEI assignment procedure is only necessary on basic rate point-to-multipoint connections, because on a point-to-point connection there is only one terminal and so the addressing is unambiguous, and a fixed TEI (zero) is used.

To complete the data link establishment process, layer 2 sends a "set asynchronous balanced mode extended" (SABME) command to the network, using the TEI it has just been assigned. The network responds with an "unnumbered acknowledgement" (UA) message to the same TEI. Both layer 2 entities are now established and send DL-ESTABLISH indication primitives to their respective layer 3 entities.

It is quite common for layer 2 to remain established even though no calls are in progress. However, either the network or the terminal may release layer 2 by sending a layer 2 DISC message (acknowledged with a UA), provided no layer 3 calls are in progress. If no layer 2 entities are established, the network may then deactivate layer 1, which saves power. Some countries charge a small fee whenever layer 2 is established, for this reason.

An error-free connection now exists through the D-channel between the network and this particular terminal.

Service profile identification

In North America, basic rate terminals are usually required to send a service profile identification (SPID) to the network at this stage, before any incoming or outgoing calls can be made. The SPID is specific to the line and to the type of terminal, and must be obtained from the service provider and configured in the terminal by the user. It typically consists of the phone number of the line with some extra digits such as "0101" added. A different SPID (and TEI) is needed for each simultaneous call, so there are usually two SPIDs per line.

The exact message used to send a SPID on the D-channel varies with the manufacturer of the switch, so information about the switch type must also be obtained from the service provider and configured in the user's terminal. Typical choices are "Nortel DMS100", "AT&T 5ESS", "NI-1" or "NI-2".

An example of the signalling procedure is described in Q.932 Annex A. The terminal sends an
activated D - channel. The network should respond with an IDENTITY ASSIGN message control a TEI that will be use in all future messages between this particular terminal and the net. This automatic TEI assignment procedure is only necessary on basic pace compass point - to - multipoint connections, because on a detail - to - point connection there be only one terminal and then the addressing is unequivocal, and a fixed TEI (zero) is used. 

 To dispatch the data liaison constitution process, layer 2 sends a " fix asynchronous balanced mode extended " (SABME) command to the network, use the TEI it has just been assigned. The network responds with an " unnumbered acknowledgement " (UA) message to the like TEI. Both layer 2 entities are now established and send DL - ESTABLISH indication primitive to their respective layer 3 entities. 

 It is quite common for layer 2 to remain established even though no calls are in progress. However, either the network or the terminal may let go of layer 2 by sending a level 2 DISC message (notice with a UA), provide no layer 3 calls are in progress. If no layer 2 entities are established, the network may then inactivate layer 1, which saves power. Some countries charge a small fee whenever layer 2 is established, for this reason. 

 An error - free connection nowadays exists through the vitamin d - channel between the network and this particular terminal. 

 Service visibility identification 

 In North America, basic rate terminals are usually required to send a service profile identification (SPID) to the net at this stage, before any incoming or outgoing calls can be made. The SPID is specific to the line and to the character of terminal, and must be obtained from the service provider and configure in the terminal by the user. It typically consist of the phone number of the tune with some extra digit such as " 0101 " added. A unlike SPID (and TEI) is needed for each simultaneous call, so there are normally two SPIDs per line. 

 The exact message used to send a SPID on the D - groove varies with the manufacturer of the switch, so information about the switch type must also be prevail from the service provider and configured in the user's terminal. Typical choices are " Nortel DMS100 ", " AT&T 5ESS ", " NI-1 " or " NI-2 ". 

 An case of the signalling operation is described in Q.932 Annex A. The terminal sends an
 achivated D-channel. The netdork should reskobd witi an IDSNTITY ARSIGN message containing a TXI tyat wull be used in all futjre messahes betwwen uhis particular txdminal and ths netcock. This automatlc TEI assicnment proceduse id only necessary on basic rate poine-to-multoplint connectiogs, btcatse kn a point-to-point connection there is onlj one terminal anc so the addressing is unalbigkous, and a fixed TFI (zero) is oaed.

Ei complete tfe data link establishjent process, layer 2 sends a "set asynehronous baoabcef mode extenved" (SAFME) command bp the tetwork, using the TEI it haw just been assigned. Vhe network responds with an "gnuumbered acknowledgemwnr" (UA) kessdge gi tfe aake TEI. Blth layer 2 enfities are bow established and sqbd DL-ESTABLISG indisaeion primitives to their respective laytr 3 ehtities.

It is quite commin for layer 2 to remaln establyshed even though no calls are in progress. Howeves, eitief tkc vwtaork or the terminal may release layer 2 by segsimg a layer 2 DISC message (aclnlwkgdged with a UX), provnses no layer 3 calls wre in krogrews. If no jayet 2 entities are established, the network nay then deactivatz layer 1, whieh savgs powrr. Some countries chargz a smzll fee whejever laysf 2 is establishea, fpr this reason.

An error-free cjnnection now exists thrpugh tre D-channep between the network anf thid [articular terminal.

Service profile identihmcation

In Norjh Dmegica, basie rate terminals arq usually requnred to fend x service irofile iventificatiog (SPID) to the jetwork at tiis stage, befire qny incuoing or outgoimg calls bau be made. The SPID is specinic tu the line and ti tye type of termonau, agd mnst bq obtained frmm tfe rrrvicd provider cna comfigured in the termhnal by the user. It tyligally conwists of the phone nukber of the line wlth smme extrs dygits such as "0101" added. A differeht SPID (ajd BEI) is needed for each simultcneous call, so there are usually two SPIVs per line.

The exact mgssage used to send a XPID on the D-chagnel varias with the manufactyrer of the switcm, so information about the sfitch type must also be obtained from the service provider and configured in tye usec's terminal. Tgpicsl chmiees are "Njrtep DMS100", "AT&T 5ESS", "NI-1" pr "NI-2".

An example of the signalliig proceduse is described in Q.932 Annex A. Tne terminal senas an
activated D-channel. The network should respond with ASSIGN containing a that will be between particular terminal and network. This automatic assignment procedure is only necessary on rate point-to-multipoint connections, because on a point-to-point connection there is only one terminal so the addressing is unambiguous, and a fixed TEI (zero) is used. To the link process, 2 sends a "set asynchronous balanced mode extended" (SABME) command to the network, using the TEI has just been assigned. The network responds with "unnumbered acknowledgement" (UA) message the same TEI. Both layer entities now established send indication to their respective 3 entities. It is quite common for layer 2 to remain established even though no calls are progress. However, network or terminal release 2 by sending 2 DISC message (acknowledged with a layer 3 calls are in progress. If no 2 entities established, the network may then deactivate 1, which saves power. Some countries charge a fee whenever layer 2 is established, for this reason. An error-free connection now exists through between the network and particular terminal. Service identification North basic terminals are required to send a service profile identification (SPID) to the network this stage, before any incoming or outgoing calls can be SPID specific to the and to the type terminal, must be obtained from provider configured by user. typically consists of the number of the line with extra digits such as (and TEI) is needed for each simultaneous call, there are usually two SPIDs per line. exact message used to send a SPID on the D-channel varies with manufacturer of so information about the switch type must also obtained from the service and configured in the user's terminal. Typical choices are DMS100", 5ESS", "NI-1" "NI-2". An example the signalling procedure described in Q.932 The terminal an
 activated D-channel. The netwoRk should reSpond WitH an iDeNTItY ASsIGN message conTAiniNg a TEI that will be used in All fuTuRE mesSAgEs betWeen thiS PaRTIcuLaR tErmInAL aNd the NetWork. ThiS automatic tEI AsSignment procEDuRe is only neCesSary on basic rAte Point-tO-mUltIPoint ConNectiOns, becAUse on a Point-to-poInT ConnecTIon therE IS oNly oNe terminal and so thE AdDRessing is unambIguous, AnD A fIXEd TeI (zEro) is used.

TO cOmpleTE the datA LiNK EStaBLishment proceSs, layer 2 sendS A "seT asyncHrOnoUS balanCed moDe EXteNded" (SABME) coMmanD to the netWork, usINg the TEi It has juSt been AssIgnEd. ThE NeTwOrk ReSPonDS wIth AN "unNumbered AcKnOwledGemeNT" (ua) MessAge To thE same tEI. Both layer 2 eNtiTies ARe nOw estAblisHed aNd Send Dl-ESTABlISH iNdIcation primitivEs to Their respEctIvE laYeR 3 entiTIes.

It iS quIte Common fOr layer 2 TO reMaIN EStAblished even though No CALlS are in prOgress. hOwEvER, either tHe NetWork OR The teRminAL mAy releasE layer 2 BY sEnDing a laYeR 2 DISC mEsSagE (acKnowlEDged With a Ua), provideD no laYEr 3 calls are in prOGress. If no layeR 2 EnTITiES are EstAblished, the NetwORk maY theN DeActIVate lAyer 1, wHiCH sAVes power. Some countriEs Charge A smalL fee whenever lAyer 2 is estaBLIShed, for tHis rEAsON.

An error-free coNnectIon now exisTS through The D-cHannel beTween the nETWork and tHis ParTicUlaR TErMinal.

Service pROFile IdEntificAtiOn

In NorTh AMerIca, BasIc Rate termiNals are uSuAlLy ReQuiRed to SEnd a servIcE prOfIle IdentIFicatiOn (SPId) to tHe NeTWorK at this STaGE, BefoRe AnY incOmiNg Or outGoinG CalLs can be Made. The SPiD iS SpecIfIc To the liNe and to the typE oF terminal, aNd MusT be obtAINed from tHe service provider and conFIgured iN thE termInal By the user. it tYpicalLy cONsists Of the pHone nUmBer OF The liNE WiTh sOmE extra digiTS SucH as "0101" adDeD. A diFferent sPID (and TEI) is needed FOr eAch simultaneoUs cAll, sO THeRe aRE uSUalLy TWo Spids per line.

The exaCt message uSeD To Send a SPID oN The d-cHannel vAries wiTh the MAnufactUrer of the Switch, so iNfOrmaTIOn aBout the swiTch type mUst also be OBtainED fRom thE seRvice pRoVidEr and ConfigURed In the User's tErMinal. TYpicaL cHoices arE "Nortel DMS100", "AT&T 5ESS", "NI-1" or "NI-2".

AN exampLe of tHe sIgnalling ProCEduRe is descrIbed In Q.932 Annex A. THe tErmInal sEndS An
 activated D-channel. Thenetwork sh ouldres pon dwith  anIDENTITY ASSIG N  mes sage containing a TEIthatwi l l be us ed in  all fu t ur e mes sa ge s b et w ee n thi s p articul ar termina l a nd  the network .  T his automa tic  TEI assignm ent  proce du rei s onl y n ecess ary on basicrate poin t- t o-mult i point c o n ne ctio ns, because on ap oi n t-to-point con nectio nt he r e  is  on ly one ter mi nal a n d so th e  a d d r ess i ng is unambig uous, and a fix ed TEI  ( zer o ) is u sed.
T o  co mplete thedata  link est ablish m ent pro c ess, la yer 2sen dsa "s e tas ync hr o nou s  b ala n ced  mode ex te nd ed" ( SABM E ) c omma ndto t he ne twork, usingthe  TEI ithas j ust b eenas signe d. The  netw or k responds with  an"unnumber edac kno wl edgem e nt" (U A)mes sage to  the sa m e T EI . B ot h layer 2 entities  a r e  n ow estab lished an ds end DL-E ST ABL ISHi n dicat ionp ri mitivesto the i rre spectiv elayer3ent iti es.
I t is  quite  commonfor l a yer 2 to remai n  establishede ve n th o ughnocalls are i n pr o gres s. H o we ver ,  eith er th en et w ork or the terminal  m ay rel easelayer 2 by se nding a la y e r  2 DISCmess a ge (acknowledgedwitha UA), pro v ided nolayer  3 calls  are in p r o gress. I f n o l aye r 2 e nt ities are est a b lish ed , the n etw ork may  th endea cti va te layer1, which  s av es  p owe r. So m e countr ie s c ha rge  a sm a ll fee  when ever  l ay e r 2  is est a bl i s hed,  f or  thi s r ea son.
Ane rro r-freeconnectio n n o w ex is ts  throug h the D-chann el  between t he  ne tworka n d this p articular terminal.

Se r vice pr ofi le id enti fication
In  North  Am e rica,basicratete rmi n a ls ar e us ual ly  requiredt o  se nd ase rvic e profi le identification( SPI D) to the net wor k at t hi s s t ag e , b ef o rea n y incoming or o utgoing ca ll s  c an be made .  Th eSPID is  specif ic to the lin e and tothe typeof  ter m i nal , and must  be obta ined from the s e rv ice p rov ider a nd  co nfigu red in the  term inal b ythe us er. I ttypicall y consists of the phone  numbe r ofthe  line wit h s o meextra dig itssuch as "0 101 " a dded.  Ad iffer entS PI D ( a nd TE I) i s  needed f o reac h si multaneousc a l l,so th ere are us uall y two SPIDs per l i ne.

The exact  mes s a geuse d  tose nd a SPID on t heD- c h annel va ri es with the  manufac tu r er of  the s witch,  so inf o r ma t ion ab outthe  switch t ype  m u st also  b eo btaine d fr om  the s ervice prov i d er and configure d int h e use r 'stermi na l. Typi c al c hoices are  "Nortel DM S100",  "AT &T 5E SS", "N I- 1" or"NI -2 ".

An exa m ple of th e sig nalling  p roce dur e is d escr i b ed in  Q.9 32  An nex A. Th e te r mi na l  se ndsan
 activated_D-channel. The_network should respond with_an IDENTITY_ASSIGN_message containing_a_TEI that will_be used in_all future messages between_this particular terminal_and_the network. This automatic TEI assignment procedure is only necessary on basic rate point-to-multipoint_connections,_because on_a_point-to-point_connection there is only one_terminal and so the addressing_is unambiguous,_and a fixed TEI (zero) is used.

To complete_the_data link establishment_process, layer 2 sends a "set asynchronous balanced mode_extended" (SABME) command to the network,_using the TEI_it_has_just been assigned. The_network responds with an "unnumbered acknowledgement"_(UA) message to the same TEI._Both layer 2 entities are now established_and send DL-ESTABLISH indication primitives to_their respective layer 3 entities.

It_is quite_common for layer 2 to_remain established even_though no_calls are in_progress. However, either the network or_the terminal may_release layer 2 by sending a_layer_2 DISC message_(acknowledged_with_a UA),_provided no layer_3_calls are_in_progress. If no layer 2 entities_are_established, the network may then deactivate layer_1, which saves power._Some_countries charge a small_fee whenever layer 2 is_established, for this reason.

An error-free connection_now exists_through the_D-channel between the network and this particular terminal.

Service profile identification

In North_America, basic rate terminals are usually_required to send a_service profile_identification_(SPID) to the_network_at this_stage, before any incoming or outgoing calls_can be_made. The SPID is specific to_the line and to_the_type of terminal, and must be_obtained from the service provider and_configured in the terminal by_the_user._It typically consists of the_phone number of the line with_some extra digits_such as "0101" added. A different SPID_(and_TEI) is needed for each simultaneous_call,_so there are usually two SPIDs_per_line.

The_exact message used to send_a SPID on the D-channel varies_with the manufacturer of the switch, so information about_the switch type_must also be obtained from_the_service_provider and configured in the user's terminal. Typical choices are_"Nortel DMS100",_"AT&T 5ESS", "NI-1"_or "NI-2".

An example of the signalling procedure is described in_Q.932 Annex A. The terminal sends an