- Question: How far can an IP phone be located from the host?
-
Answer: There are no hard distance limitations. However delays
limit the practical distance: The larger the distance between the host
and the IP workpoint, the more delay is introduced via the underlying
network. If possible one way delays should be less than 200ms.
- Question: How many IP phones are supported per OpenScape 4000?
-
Answer: Up to 12000 IP phones can be supported per OpenScape
4000. Note that the HG 3500 is supported on all IP Access Points.
- Question: How many IP phones can be supported per HG 3500?
-
Answer: A maximum of 240 IP phones can be supported per HG 3500.
Depending on the traffic requirements of the subscribers either a 60
connection GW or a 120 connection GW will be required.
- Question: Are calls between IP phones switched in the IP network?
-
Answer: Yes. HG 3500 gateways support peer-to-peer (IP switching).
- Question: Do IP phones connected to HG 3500 gateways support mobility?
-
Answer: Yes. The following is possible:
- The user can take an IP phone to a new office or location and all relevant
information is transferred automatically and no manual intervention is
necessary.
- A user can log in from any location via a soft-client to his workpoint,
which will automatically disconnect itself from the OpenScape 4000 gateway.
The soft-client will provide the user with the same features and privileges
as the standard workpoint.
- A user can log in from any IP phone within a system or CorNet network
and make this phone his temporary phone. The home phone will automatically
be logged off and calls to the home phone are forwarded as defined for
CFNR (Call Forwarding No Reply). The temporary phone will provide the
user with the same features and privileges as the standard home workpoint.
- Question: Do the Phones require static IP addresses?
-
Answer: No, the current version of the HG 3500 line gateway does
support clients configured for DHCP. Note that a DHCP server has to be
configured in the IP network; otherwise static IP addresses are required
for all clients.
- Question: Can I connect a user via a wireless connection?
-
Answer: Yes. Given that IP line gateways support standard TCP/IP
protocol and have been designed to work over WAN links only excessive
delays are a concern. Make sure that wireless transceivers are working
like Ethernet bridges in order to minimize delays.
- Question: When payload and/or signaling IP packets arrive out of
sequence, are they automatically re-arranged?
-
Answer: As long as all the relevant payload IP packets are still
held within the jitter buffer, out of sequence IP packets will be re-arranged
automatically. Given that signaling is using TCP/IP out of sequence packets
are correctly processed by the protocol.
- Question: Which protocols are we using for signaling and QOS?
-
Answer: Signaling: TCP/IP, QOS: LAN-tagging according IEEE 802.1p/q;
DiffServ according to RFC 2474.
- Question: Is the H.323 fast connect procedure implemented on the
HG 3500?
-
Answer: Yes, in order to minimize call setup time, the H.323
fast connect procedure is used to exchange H.245 logical channel information.
- Question: If IP network is down and the 4000 does not see the IP
phones what do callers get when calling?
-
Answer: If connectivity to the IP phone is lost, the phone will
be in a reset state trying to reconnect to the gatekeeper. There is a
display indicating that state. There will be no dial tone. Incoming calls
can be re-directed using the feature “Alternate Routing On Error”
that can use LCR rules for forwarding the call to anything you like,
e.g. to PhoneMail.
- Question: Do we have QoS/payload monitoring of the DMC connection?
-
Answer: No, the HG 3500 is not aware of DMC connections.
- Question: How long does it take for IP phones to re-register with
a gateway?
-
Answer: Based on performance testing with HG 3500s, it takes
approximately 2 - 3 minutes for 240 phones to re-register onto a backup
card.
- Question: Why can’t we support more than 240 users on the 120
connection version?
-
Answer: Based on traffic values you could support over 600 users
at 6 C.C.S and 1% blocking. However you would not be able to support
the signaling traffic required for that many users. Customers would not
configure that many users on a single card for reliability reasons either.
- Question: The effect of default setting recommended by popular
router manufacturers and the TOS byte default values documented for HFA,
that is, the pre-defined DiffServ CodePoints (DSCP) is exactly the opposite
of the intended effect. The packets we marked as high priority are rejected
straightaway by the router. What is this nonsense about?
-
Answer: The default values used for HFA come from an internal
company standard that was implemented in all HG 35xx gateways. The interoperability
problem has since come to light with the result that the company standard
will be modified shortly. The default values can be modified at any time
and modified in line with actual conditions in the customer network.
- Question: Does HFA support VLANs?
-
Answer: Yes but only in conjunction with priority tagging. In
accordance with IEEE 802.1 p/q, tagging was introduced for HFA to support
priority tagging. If tagging is activated then the permanently preset
priority bits of the various types of traffic are always set. If tagging
is active, the VLAN ID can also be set (default value is zero). VLAN
ID is not supported without the set priority bits.
- Question: Does HFA support subnetting (RFC 950)?
-
Answer: Yes. When the network mask is entered, a check is performed
to determine whether the block of ones that has been set meets the minimum
length required for the class of the address, i.e. 8 ones for Class A,
16 for B and 24 for C. If the number of ones is greater than the number
required for the class, subnetting is activated.
- Question: Does HG 3500 gateway (STMI2/STM4/STMIX/STMIY) supports ClassLessInterDomainRouting
(CIDR), this means Subnetting/Supernetting?
-
Answer: Yes.
- Question: Does vHG 3500 gateway (OpenScape 4000 SoftGate) supports
ClassLessInterDomainRouting (CIDR), this means Subnetting/Supernetting?
