Fix mistypes

Change-Id: I87da6bec137c7be37ec748ec1f9f8d072517022d

common/chapters/cell-broadcast.adoc

@@ -18,7 +18,7 @@ specification is <<3gpp-ts-23-041>>.
 === Use Cases
 
 Cell Broadcast was used for various different use cases primarily in
-the 1990ies and early 2000s, including
+the 1990s and early 2000s, including
 
 * advertisement of the GPS position of the cell tower you're currently camping on
 * advertisement of the calling codes of your current "home zone", i.e. a

common/chapters/preface.adoc

@@ -1,7 +1,7 @@
 == Foreword
 
 Digital cellular networks based on the GSM specification were designed
-in the late 1980ies and first deployed in the early 1990ies in Europe.
+in the late 1980s and first deployed in the early 1990s in Europe.
 Over the last 25 years, hundreds of networks were established globally
 and billions of subscribers have joined the associated networks.
 

common/chapters/sigtran-osmocom.adoc

@@ -38,7 +38,7 @@ Protocol.
 ==== The present (2017)
 
 In 2017, sysmocom was tasked with implementing a 3GPP AoIP compliant A
-interface.  This meant that lot of things had to change in the
+interface.  This meant that a lot of things had to change in the
 existing code:
 
 * removal of the existing hard-wired SCCPlite/IPA code from OsmoBSC
@@ -112,7 +112,7 @@ the corresponding xUA Server (<<xua-server>>) must be configured with
 `accept-asp-connections dynamic-permitted`.
 
 To enable dynamic registration of routing keys via RKM, the
-corresponding SS7 Instance (<<ss7-instance>>) must be confgured with
+corresponding SS7 Instance (<<ss7-instance>>) must be configured with
 `xua rkm routing-key-allocation dynamic-permitted`.
 
 This is of course highly insecure and can only be used in trusted,
@@ -349,7 +349,7 @@ An AS has the following properties:
 |Recovery Timeout|Duration of the AS T(r) recovery timer.  During this time,
                   outgoing messages are queued. If the AS is ACTIVE
                   before timer expiration, the queue is drained.  At
-                  expriation, the queue is flushed.
+                  expiration, the queue is flushed.
 |State|Application Server State (Down, Inactive, Active, Pending)
 |ASPs|Which ASPs are permitted to transfer traffic for this AS
 |====
@@ -360,7 +360,7 @@ An Application Server Process corresponds to a given SCTP (or TCP)
 connection.  From the STP/SG (Server) point-of-view, those are
 incoming connections from Application Servers such as the BSCs.  From
 the ASP (Client) Point of view, it has one `osmo_ss7_asp` object for
-each outbound SIGTARN connection.
+each outbound SIGTRAN connection.
 
 An ASP has the following properties:
 

common/chapters/sigtran.adoc

@@ -33,7 +33,7 @@ On top of the Physical Layer is the Message Transfer Part (MTP).
 === Message Transfer Part (MTP)
 
 MTP is the lower layer of the SS7 protocol stack.  It is comprised of
-two sub-layes, called MTP2 and MTP3.
+two sub-layers, called MTP2 and MTP3.
 
 Nodes in a MTP network are addressed by their unique PC (Point Code).
 
@@ -54,7 +54,7 @@ Linkset exist both for load sharing as well as for fail over purposes.
 ==== Point Codes
 
 The length of point codes depends on the particular MTP dialect that
-is used.  In the 1980ies, when international telephony signaling
+is used.  In the 1980s, when international telephony signaling
 networks were established, most countries had their own national
 dialects with certain specifics.
 
@@ -210,7 +210,7 @@ to the network, such as HLR or MSC) were attached to the existing old
 SS7 backbone by means as SUA and M3UA.  Over time, even the links of
 the actual network backbone networks became more and more IP based.
 
-In order to replace existing TDM-based SS7 links/liksets with SIGTRAN,
+In order to replace existing TDM-based SS7 links/linksets with SIGTRAN,
 the M2UA or M2PA variants are used as a kind of drop-in replacement
 for physical links.
 
@@ -334,7 +334,7 @@ stackings) operates on top of both IPv4 and IPv6.  As the entire
 underlying IP transport is transparent to the SS7/SCCP applications,
 there is no restriction on whether to use SIGTRAN over IPv4 or IPv6.
 
-==== SCTP multi-homing in SIGTARN
+==== SCTP multi-homing in SIGTRAN
 
 SCTP, unlike more traditional IP L4 protocols (TCP, UDP) doesn't work
 based on a _connection_ between source IP:port and Destination IP:port.