Lucent Technologies Ds1/Cept1/Isdn Pri Reference Manual

DEFINITY Communications System Generic 2.2 and Generic 3 V2 
DS1/CEPT1/ISDN PRI Reference  
555-025-107  Issue 1
July 1993
Layers 2 and 3 
Page 5-15 ISDN PRI Layer 3 
5
1. Assign interface identifier 0 to each board containing a D 
c hannel.
2. Assign interface identifier 1 to each board containing a 
b ac kup  D c hannel.
3. For eac h b oard  c ontaining  all B c hannels, assig n an 
interfac e id entifier. Assig n id entifiers sequentially starting  
with 2 if the D c hannel g roup  has a b ac kup  D c...

DEFINITY Communications System Generic 2.2 and Generic 3 V2 
DS1/CEPT1/ISDN PRI Reference  
555-025-107  Issue 1
July 1993
Layers 2 and 3 
Page 5-16 ISDN PRI Layer 3 
5
nIn the Group Memb er Assig nments p ag e of the ISDN PRI trunk g roup  
form, p ut the d esired  sig naling  g roup of the trunk into the Sig Grp
 field s. 
The entry in this field must be a signaling group containing the board 
c ontaining  this trunk member. If the memb ers on a b oard  are in only one 
signaling  g roup , this...

DEFINITY Communications System Generic 2.2 and Generic 3 V2 
DS1/CEPT1/ISDN PRI Reference  
555-025-107  Issue 1
July 1993
Layers 2 and 3 
Page 5-17 ISDN PRI Layer 3 
5
end  will simp ly d rop  them. If you need  these IEs, however, you should  use the 
user-network protocol. 
For more information on these information elements and  how they are used , see 
the sec tion ‘‘Call Control Messages’’
 later in this c hap ter.
Bec ause the p eer protoc ol d oes not sup p ort these information elements and  for...

DEFINITY Communications System Generic 2.2 and Generic 3 V2 
DS1/CEPT1/ISDN PRI Reference  
555-025-107  Issue 1
July 1993
Layers 2 and 3 
Page 5-18 ISDN PRI Layer 3 
5
simultaneous seizing  of a trunk b y b oth end s. In g eneral, g lare c an b e hand led  in 
one of the following  ways:
nOne sid e wins and  seizes the trunk while the losing  side c all fails. In this 
c ase, the losing  system c an take ac tions suc h as automatic ally retry the 
c all or simp ly ap p ly reord er tone.
nOne sid e wins...

DEFINITY Communications System Generic 2.2 and Generic 3 V2 
DS1/CEPT1/ISDN PRI Reference  
555-025-107  Issue 1
July 1993
Layers 2 and 3 
Page 5-19 ISDN PRI Layer 3 
5
G2.2 Protocol and Glare Handling
In the G2.2 p eer p rotoc ol, the G2.2 is always the user sid e at layer 3 and  is not 
c ontrollab le b y ad ministration. In a g lare situation the G2.2 uses the layer 2 
network-user b it setting  in p roc ed ure 262, word  1, field  6 to d etermine if it wins or 
loses. If it is set to network, it wins...

DEFINITY Communications System Generic 2.2 and Generic 3 V2 
DS1/CEPT1/ISDN PRI Reference  
555-025-107  Issue 1
July 1993
Layers 2 and 3 
Page 5-20 ISDN PRI Layer 3 
5
— If the G3V2 find s an alternate B c hannel it send s a resp onse to the 
inc oming  SETUP message ind ic ating  the alternate B c hannel.
— If the G3V2 c annot find  an alternate B c hannel it drop s the inc oming  
call.
2. If the G3V2s outg oing  c all wins and  the inc oming  (losing ) c all is c od ed  as 
exc lusive, the G3V2 drops...

DEFINITY Communications System Generic 2.2 and Generic 3 V2 
DS1/CEPT1/ISDN PRI Reference  
555-025-107  Issue 1
July 1993
Layers 2 and 3 
Page 5-21 ISDN PRI Layer 3 
5
Another b etter method  to minimize the oc c urrenc e of g lare on ISDN PRI trunks is 
availab le only in G3V2. In G3V2 you c an ad minister the trunk hunting  d irec tion for 
the ISDN PRI trunk group  as asc end ing  on one system and  as d esc end ing  on the 
other system. This will make it unlikely that the same trunk (B c hannel)...

DEFINITY Communications System Generic 2.2 and Generic 3 V2 
DS1/CEPT1/ISDN PRI Reference  
555-025-107  Issue 1
July 1993
Layers 2 and 3 
Page 5-22 ISDN PRI Layer 3 
5
nAdvantages
— No resourc es are tied  up  for c alls not c omp letely d ialed  
(ab and oned  c alls).
— Call hold ing  times are shortened.
nDisadvantages
— Call setup  times (the time from the last d ialed  d ig it to alerting on the 
far end ) will leng then for non-ISDN PRI c alls, esp ec ially over 
d ial-p ulse trunks.
— Trunk...

DEFINITY Communications System Generic 2.2 and Generic 3 V2 
DS1/CEPT1/ISDN PRI Reference  
555-025-107  Issue 1
July 1993
Layers 2 and 3 
Page 5-23 ISDN PRI Layer 3 
5
d isp lays. The IEs used  for user-to-user information sig naling  are d esc rib ed later 
in the sec tion ‘‘User-to-User Information Sig naling ’’
.
The first three information elements of all ISDN PRI messages are the same — 
the p rotoc ol d isc riminator IE followed  b y the c all referenc e value IE, followed  b y 
the message typ e...

DEFINITY Communications System Generic 2.2 and Generic 3 V2 
DS1/CEPT1/ISDN PRI Reference  
555-025-107  Issue 1
July 1993
Layers 2 and 3 
Page 5-24 ISDN PRI Layer 3 
5
c ould  return the c ause value for bearer capability not implemented
 in 
the DISCONNECT messag e. Cause values are valid  in only some messag es. The 
list of c ause values and their meaning s c an b e found  in the Q.931 sp ec ific ations. 
Note that the titles of the c ause values sug g est the situations in whic h they 
should  b e...