Telco Provisioning Overview Of Inter-Site Links - HP StorageWorks 12000 - Virtual Library System EVA Gateway Manual

Initial Link
backup speed in
size in Mb/sec
GB
500
1000
100
1000
500
1000
* = Unac-
ceptable
usage
model
Depending on the size of the full backup and the link speeds deployed, D2D can deliver the replication
in either a 12 hour window (at 100% link utilization) or 24 hour window (with 25% link utilization).
Areas marked with an asterisk are outside of these stated usage models. A 1000 Mbit/sec link
represents the link speed used when co-locating the devices for initialization.
Telco Provisioning
This section provides an overview of how Telcos provide WAN links. With HP D2D device replication
the typical parameters required to be specified to the Telco are:
• Physical location with respect to a Telco Point of Presence. It is often said that it is the last 100 m
of a WAN link where all the cost is incurred. A Point of Presence (PoP) is where the Telco has a
connection point to their Core infrastructure. Generally this is housed in the same building as their
telephone exchanges. Sometimes laying in the copper or fibre from a Telco's point of presence
to your building is where the majority of the installation costs are incurred. The physical location
of your office or disaster recovery site will definitely have an effect of the link price. Needless to
say if your premises already have a link in place then generally increasing the bandwidth of an
existing link is relatively easy. Most Telcos require a business to be within 25 km of a point of
presence for Ethernet connections.
• Speed required Most D2D replication implementations will not require links above 50 Mbits/sec.
Many will be able to function adequately on speeds as low as 2 Mbit/sec links.
90 D2D Systems
Backup Initial.
time at time via
25 WAN in
MB/sec hours
in hours (66% effi-
ciency
unconten-
ded),
compres-
sion at
1.5:1,
deduplic-
ation at
1.5:1,
local
backups
in pro-
gress
5.6 14.8
11.1 29.7
1.1 1.0
5.6 5.0
11.1 9.9
Overview of Inter-Site Links
Initial. Ongoing Limiting
time via replica- factor in
co-loca- tion time replica-
tion in in hours tion
hours, (1% Data
replica- change
tion on rate)
GbE unconten-
ded link
(100%
utiliza-
tion)
5.0 2.1
9.9 4.3
D2D ap-
1.0 0.4
pliance
5.0 2.1
9.9 4.3
Ongoing Limiting
replica- factor in
tion time replica-
in hours tion
(1% data
change
rate) —
25% util-
ization
link
2.5
4.9
D2D ap-
0.4
pliance
2.1
4.3