DEFINITY Enterprise Communications Server Release 7
Maintenance for R7r
555-230-126 Issue 4
June 1999
Maintenance Architecture
1-25SPE Duplication
1
When shadowing into the standby SPE has been off (as when the system first
comes up), system software chec ks to see if it is safe to restore shadowing .
Handshake communication m ust be up. Then software verifies (with Test #920)
that the SPEs have identical hardware configurations. If this passes and there are
no shadow-relevant component fa ilures, system software turns on shadowing
again.
Once shadowing is tur ned on, it is necessary to refresh the c ontents of standby
memory to bring it into full ag reement with the active’s by c opying every word of
acti ve SPE mem ory t o the s tand by. Thi s take s ap prox imate ly 5 m inute s, tho ugh
traff ic lo ad c an in crea se the dura tion. When c omp lete d, th e stan dby SPE is sa id
to be "refreshed". status spe or the

Stand by SPE Sta tus Qu ery Test (#855 )

in the
STBY-SPE tes t seq uenc e ca n be used to c hec k the REFRESH stat us of t he
standby. Unless the standby SPE is refreshed, interchange into it can disrupt
service for several minutes. Otherwise, interc hanges are minimally disrup tive. A
standby SPE exiting lock mode or just released from busyout must underg o this
full re-initialization.
System software tracks the operation and raises a major alarm when refresh
failure occurs. If shadowing stays on, system software automatically tries to
refresh again 5 minutes later.
Generally, memory shadowing should always remain on. But there are c onditions
when the system legitimately operates with s hadowing off:
■The standby SPE is undergoing any restart.
■The ac tive SPE i s und erg oing a res tart level of 2 or grea ter.
■The ac tive SPE i s loc ked .
■The standby SPE is busied out.
In any other situation, it is an error condition for shad owing to be off. The first 2
situations are transitory and shadowi ng should automatical ly be restored within
10 minutes. If shadowing has b een on for several minutes, it is an error cond ition
for the standby not to be refreshed .
Initialization: Bringing the Standby SPE Up
When th e stan db y SPE has b een o ut of s ervi ce or is fir st c oming up, SPE
software executes the following step s:
1. Establishes handshake communic ation.
2. When SMM answers handshake, raises the standby SPE’s SOH to

not

refreshed

if it has no critical c omponent alarms, or
partially functional
there are critical comp onent alarms.
3. Tests for component mismatch (test number 920).
4. If there is no mismatch, and no major alarm s against shadow-relevant
components, and if SMM p ermits, turns on memory shadowing