APPENDICES
Oki BV1250 Installation Guide
Page 286 of 334
Revision 1.0
D.3 External DNS
A BV1250 network can utilize up to three external DNS servers. As is the
case with the BV1250’s internal DNS capabilities, external DNS servers
are used to provide IP to telephone number translations. Each server can
support up to 2048 records. This capability is usually used to augment the
internal DNS functions of the BV1250 unit’s internal DNS capabilities.
The BV1250 unit’s internal DNS records should not be redundant
with the records contained in an external server. Such
redundancy can result in wasted server file space, slower look-up,
and configuration conflicts.
The BV1250 uses a dedicated cache memory that is able to store number
translation information for up to 511 units. When an external DNS server
is employed, this capability helps to speed database look-up time when
connecting to frequently called numbers.
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When both the internal and external DNS capabilities are used, the
BV1250 unit uses the following order of operations
When a number is called, the BV1250 looks in its cache memory to see if
the number has been previously called. If not found in cache, the BV1250
searches it internal DNS database (DNS.DAT) to establish the call and, if
found, records the number to cache for later use, and completes the call.
If the number is not found in the internal database, the unit queries the
external DNS server, records the information in cache for later use, and
completes the call.
DNS Server
( 2 0 4 8 r e c o r d s
m a x i m u m )
BS1200
Internal Cache
( 5 1 1 r e c o r d s
m a x i m u m )
Translation
query
Call connected
# f o u n d ?
# f o u n d ?
Y e s
N o
N o
BS1200 internal DNS
records
( 5 1 1 r e c o r d s m a x i m u m )
Y e s
R e c o r d i n
c a c h e
Up to 511 records are recorded to the internal cache using a FIFO system
(first-in, first-out). This assures that frequently called numbers are always
available in the cache, reducing connection time for subsequent calls to
the same number and this results into less delays in establishing a call.
When the internal and external DNS capabilities are used in a BV1250
network, the internal DNS record should be used for frequently called
numbers.
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The cache is cleared during equipment restart or reset.
Summary of Contents for BV1250
Page 1: ...BV1250 Internet Voice Gateway INSTALLATION GUIDE Oki Electric Industry Co Ltd...
Page 2: ......
Page 12: ...INTRODUCTION Oki BV1250 Installation Guide Page 2 of 334 Revision 1...
Page 18: ...OVERVIEW Oki BV1250 Installation Guide Page 8 of 334 Revision 1 0...
Page 20: ...PLANNING Oki BV1250 Installation Guide Page 10 of 334 Revision 1 0...
Page 142: ...FXO WORKSHEETS Oki BV1250 Installation Guide Page 132 of 334 Revision 1 0...
Page 144: ...PHYSICAL INSTALLATION Oki BV1250 Installation Guide Page 134 of 334 Revision 1 0...
Page 184: ...LOGICAL INSTALLATION Oki BV1250 Installation Guide Page 174 of 334 Revision 1 0...
Page 270: ...APPENDICES Oki BV1250 Installation Guide Page 260 of 334 Revision 1 0...
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Page 343: ...Oki BV1250 Installation Guide APPENDICES Revision 1 0 Page 333 of 334...
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