3.2.5  

CMS 
 
Caution  
Place the central control board on a flat surface before inserting the CMS subboard.  
The spacing bolts supplied guarantee the correct insertion of the subboard, so you should always mount them (see Figure 3-7).  
Otherwise you may damage the board.  

Introduction  
The Clock Module Small CMS (S30807-Q6928-X) is an optional subboard for the HiPath 3000 central control boards and guarantees greater clock accuracy.

Recommendations for CMA and CMS Utilization  
Table 3-19 provides recommendations for the implementation of CMA and CMS subboards based on
 •   the type of network (ISDN S0, ISDN S2M or Ethernet/IP (10/100 BaseT))
 •   the trunk connection available (no trunk/analog trunk, ISDN S0 or ISDN S2M) and consequently, the possible provision of a digital reference clock
 •   HiPath Cordless Office.
 Figure 3-8   Networking Options for HiPath 3000 Systems
 

 Table 3-19   Recommendations for CMA and CMS Utilization
 Trunk connection  
 Reference clock  
 HiPath Cordless Office  
   
 Trunk connection  
 Reference clock  
 HiPath Cordless Office  
  no   
 yes  
  no   
 yes  
Networking via ISDN S0 lines:  
 Master system  
   
 SLAVE system(s)  
No trunk or analog trunk  
 -  
 -  
 CMS or CMA  
 (see Table 11-1)  
No trunk or analog trunk  
 Via ISDN S0 networking line  
 -  
 CMA2  
ISDN S0  
(not always active)  
 Via ISDN S0 trunk connection  
 (if active)  
 CMS1  
 CMS or CMA  
 (see Table 11-1)  
ISDN S0  
(not always active)  
 Via ISDN S0 networking line  
 -  
 CMA2  
ISDN S0  
(always active)  
 Via ISDN S0 trunk connection  
 CMS1  
 CMA2  
ISDN S0  
(always active)  
 Via ISDN S0 trunk connection  
 -  
 CMA2  
ISDN S2M  
 Via ISDN S2M trunk connection  
 CMS1  
 CMA2  
ISDN S2M  
 Via ISDN S2M trunk connection  
 -  
 CMA2  
Networking via ISDN S2M lines:  
 Master system  
   
 SLAVE system(s)  
No trunk or analog trunk  
 -  
 -  
 CMS or CMA  
 (see Table 11-1)  
No trunk or analog trunk  
 Via ISDN S2M networking line  
 -  
 CMA2  
ISDN S0  
(not always active)  
 Via ISDN S0 trunk connection  
 (if active)  
 CMS1  
 CMS or CMA  
 (see Table 11-1)  
ISDN S0  
(not always active)  
 Via ISDN S2M networking line  
 -  
 CMA2  
ISDN S0  
(always active)  
 Via ISDN S0 trunk connection  
 CMS1  
 CMA2  
ISDN S0  
(always active)  
 Via ISDN S0 trunk connection  
 -  
 CMA2  
ISDN S2M  
 Via ISDN S2M trunk connection  
 CMS1  
 CMA2  
ISDN S2M  
 Via ISDN S2M trunk connection  
 -  
 CMA2  
Networking via Ethernet/IP (10/100 BaseT) lines:  
 System 1  
   
 System(s) n+1  
No trunk or analog trunk  
 -  
 CMS3  
 CMS or CMA  
 (see Table 11-1)  
No trunk or analog trunk  
 -  
 CMS3  
 CMS or CMA  
 (see Table 11-1)  
ISDN S0  
(not always active)  
 Via ISDN S0 trunk connection  
 (if active)  
 CMS3  
 CMS or CMA  
 (see Table 11-1)  
ISDN S0  
(not always active)  
 Via ISDN S0 trunk connection  
 (if active)  
 CMS3  
 CMS or CMA  
 (see Table 11-1)  
ISDN S0  
(always active)  
 Via ISDN S0 trunk connection  
 -  
 CMA2  
ISDN S0  
(always active)  
 Via ISDN S0 trunk connection  
 -  
 CMA2  
ISDN S2M  
 Via ISDN S2M trunk connection  
 -  
 CMA2  
ISDN S2M  
 Via ISDN S2M trunk connection  
 -  
 CMA2  
1CMS is not necessary if the reference clock supplied by the CO is always available via the networking lines (not a transparent clock).
2CMA is not necessary if ADPCM conversion is not needed for HiPath Cordless Office (see Table 11-1).
3CMS is not necessary but is recommended for the following reasons: Although an Ethernet link is an asynchronous connection, buffer overflow/underflow can cause transmission errors. To avoid this, the clock difference between the master and the slave systems should be as small as possible so that the receive and send buffer can be read and addressed at the same speed on both sides. The more accurate the clock source in the relevant systems, the fewer the faults.