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Re: LCAS and GMPLS
Greg,
> E.g., what about renumbering?
The renumbering is a LCAS element (fully LCAS controlled), that NMS or
GMPLS should not be bothered about.
Only if you want to operate VCAT with LCAS disabled, NMS/ASON/GMPLS has to
control the sequence numbers, but changes in the group size is not hitless
without LCAS.
Hereafter some information on the VCAT/LCAS associated parameters as
extracted from G.806 (02/04) and G.783 (02/04).
10.1/G.806 includes a generic specification for the VCAT/LCAS functions,
inlcuding a list of MI signals (MI: Management Information) which
management needs to control and gets reported. G.783 and G.798 specify the
technology specific functions, using the specifications in G.806 as basis.
Input MI signals:
=================
P-Xv/P-X-L_A_So_MI_LCASEnable:
The MI_LCASEnable input controls whether the LCAS functionality is enabled
for the source function (MI_LCASEnable = true) or disabled (MI_LCASEnable
= false).
P-Xv/P-X-L_A_So_MI_ProvM[1..XMT]:
The MI_ProvM[1..XMT] input controls whether a P[i]_AP at the P-Xv_AP is
provisioned to be a member of the VCG (MI_ProvM[i] = 1) or not
(MI_ProvM[i] = 0).
==> With this input parameter NMS/GNPLS controls which access points (and
thus VC-n trail termination functions) are part of the VCAT group. Note -
LCAS determines if there will be traffic routed over it.
P-Xv/P-X-L_A_So_MI_PLCTThr:
Partial loss of capacity transmit threshold associated with cPLCT fault
cause.
----------
P-Xv/P-X-L_A_Sk_MI_LCASEnable:
The MI_LCASEnable input controls whether the LCAS functionality is enabled
for the sink function (MI_LCASEnable = true) or disabled (MI_LCASEnable =
false). If LCAS is enabled, the function auto-detects which type of source
it is interfacing to. The output MI_LCAS_So_Detected reports whether the
present sink function detected an LCAS-enabled source function
(MI_LCAS_So_Detected=true) or a non-LCAS-enabled source
(MI_LCAS_So_Detected=false, see below for details). Only if both
MI_LCASEnable and MI_LCAS_So_Detected are true is the LCAS functionality
active in the function.
P-Xv/P-X-L_A_Sk_MI_ProvM[1..XMR]:
The MI_ProvM[1..XMR] input controls whether a particular one of the
available physical resources at the P-Xv_AP is provisioned to be a member
of the VCG (MI_ProvM[i] = 1) or not (MI_ProvM[i] = 0).
==> With this input parameter NMS/GMPLS controls which access points (and
thus VC-n trail termination functions) are part of the VCAT group. Note -
LCAS determines if there will be traffic routed over it.
P-Xv/P-X-L_A_Sk_MI_PLCRThr:
Partial loss of capacity receive threshold associated with cPLCR fault
cause.
P-Xv/P-X-L_A_Sk_MI_TSDEnable:
The MI_TSDEnable input controls whether the sink function uses AI_TSD[i]
indications as contributors for signalling defective members back to the
LCAS source function (MI_TSDEnable = true) or whether it ignores AI_TSD[i]
indications altogether (MI_TSDEnable = false).
P-Xv/P-X-L_A_Sk_MI_HOTime:
The MI_HOTime input controls whether the Hold-Off (HO) timer is enabled or
disabled for the sink function and, if enabled, what the value of the
timer is. If MI_HOTime = 0, the HO timer shall be disabled, if MI_HOTime 0
it shall be enabled.
P-Xv/P-X-L_A_Sk_MI_WTRTime:
The MI_WTRTime input controls whether the Wait-To-Restore (WTR) timer is
enabled or disabled for the sink function and, if enabled, what the value
of the timer is. If MI_WTRTime = 0, the WTR timer shall be disabled, if
MI_WTRTime 0 it shall be enabled.
The range of values for the HO/WTR timers is as defined in ITU-T Rec.
G.808.1.
P-X-L_TT_Sk_MI_SSF_Reported:
Controls if cSSF fault cause is reported. Typically owned by NMS.
Output MI signals:
==================
P-Xv/P-X-L_A_So_MI_XAT:
Current size of the transmitted payload.
P-Xv/P-X-L_A_So_MI_XMT
Maximum size of the transmitted payload.
P-Xv/P-X-L_A_So_MI_TxSQ[1..XMT]
Indication of which sequence number (_SQmap[i]) is being carried over a
particular P_AI (P_AI[i]) signal.
P-Xv/P-X-L_A_Sk_MI_XMR
Maximum size of the received payload.
P-Xv/P-X-L_A_Sk_MI_XAR
Current size of the received payload
P-Xv/P-X-L_A_Sk_MI_DMFI[1..XMR]
The relative delay, in MFI units, between each provisioned member and the
earliest-arriving member among those considered for the calculation
P-Xv/P-X-L_A_Sk_MI_LCAS_So_Detected
Indication if remote node supports LCAS.
P-Xv/P-X-L_A_Sk_MI_AcSQ[1..XMR]
Indication of which sequence number is being received over a particular
P_AI (P_AI[i]) signal.
Besides these VCAT/LCAS specific parameters, you need to control a subset
of the individual trail termination (e.g. S4_TT) function and the client
adaptation (e.g. S4-X/ETH_A) function parameters. E.g. for VC-4 and VC-3
TT_Sk functions:
Input MI parameters:
====================
Sn_TT_Sk_MI_TPmode
Termination Point mode to control alarm free path set up. Refer to
6.1/G.806 and 7.1.4/G.7710.
Sn_TT_Sk_MI_ExTI
Expected Trace Identifier value must be configured by GMPLS when GMPLS
sets up VC-n network connection; action is to read MI_TxTI parameter in
TT_So and carry this value to remote end to configure MI_ExTI.
Sn_TT_Sk_MI_TIMdis
Disables/Enables TIM defect detection. GMPLS should control this as part
of VC-n connection setup.
Sn_TT_Sk_MI_TIMAISdis
Disables/enables AIS insertion on TIM defect detection. GMPLS to control
this as part of VC-n connection setup.
Sn_TT_Sk_MI_RDI_Reported
Sn_TT_Sk_MI_SSF_Reported
Controls if cRDI and cSSF fault cause are reported. Typically owned by
NMS.
Sn_TT_Sk_MI_DEGTHR
Sn_TT_Sk_MI_DEGM
Sn_TT_Sk_MI_EXC_X
Sn_TT_Sk_MI_DEG_X
Bit error defect detection process configuration parameters. Must be
configured as part of connection setup; values depend on SLA.
Output MI parameters:
=====================
Sn_TT_Sk_MI_AcTI
Accepted Trace Identifier value report.
Parameters for one of the client adaptation functions (e.g. Sn/ETH_A,
G.8021) are typically outside the control of the GMPLS VC-n Group
connection setup; those parameters are under either NMS or client layer
GMPLS control.
I hope the above helps to get a feeling of what you need to control during
VC-n Group connection set up.
Note that the VCAT group can be set up as a single VC-n Group, or as
multiple, diverse routed, (smaller) VC-n (sub)Groups. E.g. a 5 VC-4 VCAT
group may be set up as a 5 VC-4 network connection group, as a 3 VC-4
netowrk connection group (VCG A) and a 2 VC-4 network connection group
(VCG B), as five individual VC-4 network connections, ... The most common
case when used to transport data will most likely be the second case: two
VCGs supporting one VCAT/LCAS group. I assume that NMS and GMPLS VC-n
connection management would set up VCG A and a VCG B, with the requirement
that both must be diverse routed.
If the VCAT group at a later stage is to be extended to 6 VC-4 members,
then for the case of VCG A and VCG B, the VCG B could be extended from 2
to 3 VC-4 network connections. You would then issue a connection
modification request for VCG B and leave VCG A untouched.
Regards,
Maarten
Greg Bernstein <gregbern@yahoo.com>
Sent by: owner-ccamp@ops.ietf.org
15-06-2005 18:04
To: Adrian Farrel <adrian@olddog.co.uk>, Diego Caviglia
<Diego.Caviglia@marconi.com>
cc: yhwkim <yhwkim@etri.re.kr>, ccamp <ccamp@ops.ietf.org>
Subject: Re: LCAS and GMPLS
Okay Adrian I'll take a first stab at the I-D based on
the e-mails to date and some of my tutorial material
from short courses and papers.
Thanks everyone for the info and particularly Maarten
for the in depth descriptions and information. I may
send you some extra questions after I digest it. I'm
particularly interested in places where we "enable
LCAS" or some entity tells LCAS to perform an "add" or
"delete" action. E.g., what about renumbering?
Sounds like there are plenty of possible solutions, so
a focus on a clear understanding of the problem space
and capabilities (which are already automated, can be
automated, or need to be commanded) is important.
Greg B.
--- Adrian Farrel <adrian@olddog.co.uk> wrote:
--- Lots of snips
I would suggest that Greg and Diego start an I-D. Call
it something like "Applicability Statement for
Operating LCAS and VCAT with GMPLS LSPs".
Include:
- Simple overview of VCAT and LCAS (no more than a
page, please)
- Simple statement of how LSPs fit into the picture
(about half a page)
- Statement of the requirements on GMPLS signaling
(about a page)
- Mechanisms and procedures (two or three pages)
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