R0106-HP MSR Router Series Layer 2 - WAN Configuration Guide(V7)

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• Negotiated—The member interface is as follows:
{ Up at the link layer.
{ Does not meet the conditions for being a Selected interface in the HDLC link bundle.
• Ready—The member interface is as follows:
{ Up at the link layer.
{ Meets the conditions for being a Selected interface.
{ Not Selected yet due to the following restrictions:
− The maximum number of Selected interfaces.
− The minimum number of Selected interfaces required for bringing up the HDLC link bundle.
− The minimum bandwidth required for bringing up the HDLC link bundle.
• Selected—The member interface is up at the link layer, meets the conditions for being Selected, and
conforms to the restrictions. Only member interfaces in Selected state can forward traffic.
If an HDLC link bundle does not contain any Selected interfaces, the HDLC link bundle interface is
brought down, and it cannot forward traffic. It will not be brought up and forward traffic until Selected
interfaces are detected in the HDLC link bundle. The bandwidth of an HDLC link bundle interface is the
total bandwidth of all Selected interfaces.
The states of HDLC link bundle member interfaces are determined according to the following rules:
1. An interface is placed in the Initial state if its link layer protocol is down.
2. An interface is placed in the Negotiated state when its link layer protocol goes up.
3. An interface in the Negotiated state might transit to the Selected or Ready state after completing the
following selection process.
4. For example:
{ The number of member interfaces in the Negotiated state is M.
{ The maximum number of Selected interfaces allowed in the HDLC link bundle is set to N.
The maximum number of Selected member interfaces allowed in a bundle is set by using the
bundle max-active links command. If the command is not set or the set value exceeds the hardware
capability, the hardware capability applies.
{ When N is no smaller than M, all the member interfaces in the Negotiated state enter the
Selected state.
{ When N is smaller than M, these member interfaces are sorted as follows:
− They are first sorted in the descending order of rates/baud rates.
− Member interfaces with the same rate/baud rate are sorted in the descending order of
bundling priorities.
− Member interfaces with the same bundling priority are sorted in the ascending order of
interface numbers.
The first N member interfaces enter the Selected state, and the remaining (M-N) member
interfaces enter the Ready state.
5. For example, the number of member interfaces meet the conditions for being Selected is P. The
minimum number of Selected interfaces required for bringing up the HDLC link bundle is set to Q.
The P interfaces will be Selected when any of the following conditions exist:
{ P is not smaller than Q.
{ The following limits are not set: