Performance Considerations For Max Stacking - Lucent Technologies MAX 6000 Network Configuration Manual

Figure 4-6. Packet flow from the Ethernet
Connection profiles within a stack
A stack does not support sharing of local Connection profiles between the MAX units in the
stack. Every MAX unit that is set up to use internal authentication must retain all
authentication information for every call. You can eliminate this requirement by using a
centralized authentication server, such as RADIUS.
Telephone numbers for new MP+ and MP-with-BACP channels
When a MAX unit has to add a channel for an MP+ or MP-with-BACP call, it provides a local
telephone number for the new channel. However, sometimes the unit that answers the call
cannot provide a local telephone number for the additional channel because all the channels
that connect directly to it are busy. In that case, the unit requests other members of the stack to
supply a telephone number for the additional channel.
An MP call does not pass telephone numbers when it adds a channel. If each unit in the stack is
accessed through a different telephone number, the originator of the call must know all of the
possible telephone numbers. An alternative in this instance is to use BACP or MP+ to obtain
the telephone number from a unit with a free channel.

Performance considerations for MAX stacking

There is no limit to the number of stacked channels in single call or in a stack of MAX units,
other than the limit for each individual unit. The MAX 6000 and the MAX 3000 units support
up to 40 stacked channels. A unit that can handle n real channels can handle n/3 stacked
channels.
There is no theoretical limit to the number of MAX units in a stack, other than performance
considerations. Because all data from stacked channels crosses the LAN, performance could
suffer with a large number of MAX units in the stack and many stacked channels in use.
Performance overhead increases when stacked bundles span multiple boxes. In a bundle of six
channels, four of which are real and two are stacked, the overhead is the actual bandwidth of
the two stacked channels (2 x 64=128K). The actual payload data of the six channels with 2:1
data compression is 6 x 2 x 64=768K. The overhead is 128 over 768, or 16%. In a two-channel
bundle with one real and one stacked channel, with the same compression, the overhead is
25%.
MAX 6000/3000 Network Configuration Guide
WAN
1
64K
3
64K
Configuring Individual WAN Connections
Configuring MP, MP+ and BACP connections
MAX #1
(master)
1
2
MAX #2
(slave)
Ethernet
10Mbps
A
4-59